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FOUNDRY WORK 



A Practical Handbook on Standard Foundry Practice, 
Including Hand and Machine Molding; Cast 
Iron, Malleable Iron, Steel, and Brass 
Castings; Foundry Manage- 
ment; Etc. 



REVISED BY 

BURTON L. GRAY 

INSTRUCTOR IN FOUNDRY PRACTICK, WORCESTER POLYTECHNIC INSTITUTE 
MEMBER, FOUNDRYMEn's ASSOCIATION 



ILLUSTRATED 



AMERICAN TECHNICAL SOCIETY 

CHICAGO 
1918 



^ 



COPYKIGHT, 1916, 1918, BY 

AMERICAN TECHNICAL SOCIETY 



COPYKIGHTED IN GKEAT BRITAIN 
ALL EIGHTS RESERVED 



M 26 (918 



©G1.A497907 






INTRODUCTION 

O 

tK nn HE making of a metal casting seems like a very simple opera- 
-■- tion — given a pattern, a flask, a supply of molding sand, and 
some molten metal; presto! it is done — but a little study de- 
^^velops the fact that there are few industries where more depends 
^ upon shop kinks and the many other essential things which make 
up a broad knowledge of a distinct trade than in foundry work. 
The industry, as such, is as old as our knowledge of brass and iron, 
N^ the former having been made into castings from earliest times. 
^ Casting methods, however, have partaken of the general mechanical 
development of the last few years and today there is no com- 
parison as to the quality of castings, the complexity of the patterns 
cast, and the speed of manufacture, with the work of a few years ago. 

^ In this article the methods of hand molding have been carefully 
discussed, including the many questions of pattern construction 
which are more or less closely associated with foundry work. The 
presentation also includes the uses of the various types of molding 
machines, which have become so popular within the last few years. 
Malleable iron practice has now become well standardized and this 
type of casting, particularly for small vrork requiring much dupli- 
cation, is very important. An excellent discussion of steel castings 
is particularly pertinent as this type of casting is fast displacing 
drop forgings for many classes of work. 

^ Altogether the article represents a well-rounded and thoroughly 
up-to-date discussion of this important subject. The original author 
and the reviser, both men of broad experience, have combined to 
give the reader the benefit of their knowledge and it is the hope of 
the publishers that the book will be found instructive and interest- 
ing to the practical foundry man as well as to the general reader. 



CONTENTS 



Molding practice X 

Main branches 1 

Molding equipment 3 

Classes 3 

Molding sand 55 

Core sand. q 

Graphite. , . 7 

Charcoal 7 

Sea coal 7 

Distinction 7 

Fire clay 7 

Parting dusts g 

Core binders 9 

Tools 9 

Flasks 9 

Shovel , 12 

Rammers 13 

Finishing tools 14 

Clamps 17 

Molding processes 18 

Sand mixture Ig 

Sifting 19 

Ramming 20 

Gating. 24 

Shrinkage heads. . 26 

Pressure in molds 27 

Common defects in castings 31 

Typical molding problems. .31 

Flat joint 32 

Coping out 35 

Sand match 36 

Split-pattern molds 38 

Floor bedding 42 

Open mold 45 



CONTENTS 

PAGE 

Core work 46 

Materials 46 

Equipment 48 

Conditions of use 50 

Methods of making 53 

Cylindrical cores : 58 

Setting chaplets 60 

Projecting cores 60 

Hanging cores 61 

Bottom-anchored cores 61 

Duplicating castings 66 

Practical requisites in hand molding 66 

Use of molding machines. . . : 67 

Dry-sand work 89 

Characteristic features 89 

Molding engine cylinder 89 

Making barrel core 92 

Loam molding 94 

Rigging 94 

Materials 97 

Principles of work 99 

Simple mold 102 

Intricate mold 104 

Casting operations. 109 

Furnace parts 109 

Blast . 112 

Running a heat 116 

Foundry ladles 118 

Pouring .119 

Chemical analysis. 123 

Calculation of mixture 124 

Fuel : 126 

Sand mixing 127 

Cleaning castings 131 

Steel work 136 

Present development 136 

Processes 136 

Characteristics of metal 136 



CONTENTS 

PAGE 

Steel molds 137 

Facing mixtures 137 

Packing 139 

Cores 141 

Steel castings 141 

Running a heat. . . 141 

Setting up molds 143 

Cleaning castings 144 

Annealing 144 

Malleable practice. ... 145 

Comparative characteristics of metal 145 

Testing 146. 

Production processes 148 

Molding methods 149 

Methods of melting 152 

Iron mixture 156 

Variation from gray-iron practice 159 

Cleaning castings 160 

Annealing 161 

Finishing 167 

Brass work 167 

Metals . . ' 168 

Mixtures .170 

Production 171 

Molding materials 171 

Equipment 172 

Examples of work 175 

Melting. : .... 176 

Cleaning 181 

Shop management 182 

Governing factors 182 

Molding divisions 184 

Materials 186 

Handling systems 186 

Cleaning department 187 

Performance 188 

Accident prevention 189 

Checking 190 

Keep's mechanical analysis 190 

Arbitration-bar tests 191 



FOUNDRY WORK 

PART I 



MOLDING PRACTICE 

Introductory. Foundry work is the name applied to that 
branch of engineering which deals with melting metal and pouring 
it in liquid form into sand molds to shape it into castings of all 
descriptions. 

In the manufacture of modern machinery three classes of 
castings are employed, each one having its individual physical 
properties, such as strength, toughness, durability, etc. These 
castings are as follows: gray iron; copper alloys, i.e., brass, bronze, 
etc. ; and mild steel. By far the greatest number of castings made 
are of gray iron, that is, iron which may be machined directly as it 
comes from the mold without any further heat treatment. 

The main purpose of this book is to explain the underlying prin- 
ciples involved in making molds for gray-iron castings, and the mix- 
ing and melting of the metals for such castings. The articles on 
Malleable Cast Iron as well as the articles on Brass Founding and 
Steel Casting emphasize only those features of the methods used 
which differ from gray-iron foundry practice. The article on Shop 
Management is intended to set students thinking on this subject; 
because the whole trend of modern shop practice is toward special- 
ization and system in handling every department of the work, in 
order to increase efficiency and reduce cost. 

DIVISIONS OF IRON MOLDING 

Main Branches. There are four main branches in gray iron 
molding: (1) green-sand work; (2) core work; (3) dry-sand molding; 
and (4) loam work. 

Green-Sand Molding. The cheapest quickest method of form- 
ing the general run of castings is by green-sand molding. Damp 
molding sand is rammed over the pattern, and suitable flasks are 
used for handling the mold. When the pattern is withdrawn the 



2 FOUNDRY WORK 

mold is finished, and the metal is pom-ed while the efficiency of the 
mold is still retained by reason of this dampness. The mold may be 
poured as soon as made; and in case of necessity it may be held over 
a day or more depending upon its size. If the sand dries out, the 
mold should not be poured. 

Core Making. Core making supplements molding. It deals 
with the construction of separate shapes in sand which form holes, 
cavities, or pockets, in the castings. Such shapes are called cores. 
They are held firmly in position by the sand of the mold itself or by 
the use of chaplets. Core sand is of a different composition from 
molding sand. It is shaped in wooden molds called core boxes. All 
cores are baked in an oven before they can be used. The whole 
detail of their construction is so different from that of a mold, that 
core making is a distinct trade — a trade, however, that is generally 
considered a stepping stone to that of molding. Boys usually begin 
to serve their time in the core shop. 

Dry-Sand Molding. Dry-sand molding is the term applied to 
that class of work where a flask is used, but a layer of core sand mix- 
ture is used as a facing next to the pattern and the joint, and the 
entire mold is baked before pouring. This drives off all moisture 
and gives hard clean surfaces to shape the iron. It is used where 
heavy work having considerable detail is to be cast> or where the 
rush of metal or the bulk of it might injure a mold of green sand. 
Dry-sand molds are usually made up one day, baked over night, and 
assembled and cast the next day. 

Loam Work. Loam work is the term applied to molds built of 
bricks carried on heavy iron plates. The facing is put on the bricks 
in the form of mortar and shaped by sweeps or patterns depending 
upon the design of the piece to be cast. All parts of the mold are 
baked, rendering the surfaces hard and clean. After being assem- 
bled, these brick molds must be rammed up on the outside with green 
sand in a pit or casing to prevent their bursting out under the casting 
pressure. Simple molds can be made up one day, assembled, rammed 
up and poured the next, but it usually takes 3 or 4 days and some- 
times as many weeks to turn out a casting. 

Loam w^ork is used for the heaviest class of iron castings for 
which, on account of the limited number wanted, or the simplicity of 
the shape, it would not pay to make complete patterns and use a 



FOUNDRY WORK 3 

flask. In some cases the intricacy of the design makes a pattern 
necessary, and size alone excludes the use of sand and flasks. 

Selection of Method, No hard and fast rules exist for the selec- 
tion of the method by which a piece will be molded. Especially 
with large work, the question whether it shall be put up in green 
sand, dry sand, or loam, often depends upon local shop conditions. 
The point to consider is: How can the best casting for the purpose 
be made for the least money, considering the facilities at hand to 
work with? 



MOLDING EQUIPMENT 
MATERIALS 

Before taking up the making of molds, let us consider briefly 
the materials used, where they are obtained, and what is their 
particular service in the mold. Also we shall describe the principal 
tools used by the molder in working up these materials into molds. 

Classes. There are three general classes of materials for mold- 
ing kept in stock in the foundry, as tabulated herewith: 

Molding Materials 



Sands 


Facings 


Miscellaneous 


Molding sands 

Light 

Medium 

Strong 
Free sands 

Sharp or Fire 

Beach sand 


Graphite 
Charcoal 
Sea coal 


Fire clay- 
Parting dust 
Burnt sand 
Charcoal 
Partainol 
Core binders 



Sands 

Quality. All sands are formed by the breaking up of rocks due 
to the action of natural forces, such as frost, wind, rain, and the 
action of water. 

Fragments of rocks on the mountain sides, broken off by action 
of frost are washed into mountain streams by rainfall. Here they 
grind against each other and pieces thus chipped off are carried by 
the rush of the current down into the rivers. Tumbled along by the 
rapid current of the upper river, the sand will finally be deposited 
where the stream flows more gently through the low land stretches 



FOUNDRY WORK 



TABLE I 
Proportions of Elements in Sands 



Elements 



(a) Silica Si02 

Alumina (clay). . ..AI2O3 

Iron oxide Fe203 

Lime oxide CaO 

(b) Lime carbonate. . CaCOs 

Magnesia MgO 

Soda NaaO 

Potash K2O 

Combined water. . . .H2O 
Organic matter 

Specific gravity 

Degree of fineness 



Fire 

Sand 

(per cent) 



98.04 

1.40 

.06 

.20 



14 



Molding Sands 



Iron Work 



Light 
(per cent) 



82.21 
9.48 
4.25 

".Q8 
.32 
.09 
.05 

2.64' 
.28 



Medium 
(per cent) 



85.85 

8.37 

2.32 

.50 

.29 

.81 

.10 

.03 

1.68 

.15 



Heavy 
(per cent) 



88.40 
6.30 
2.00 

.78 

''56 



1.73 
.04 



Brass 



Light 
(per cent) 



78.86 
7.89 
5.45 

.50 
1.46 
1.18 

.13 

.09 
3.80 

.64 



Core 

Sand 

(per cent) 



85.50 
2.65 

.85 



2.592 



2.652 

85 



2.645 



2.630 



2.640 
95 



below the hills. Here the slight agitation tends to cause the finer 
sand and the clay to settle lower and lower down in the bed. Thus 
we find beds that have been formed in ages past; possibly with a top 
soil formed over them, so long have they been deposited. But on 
removing this top soil we find gravel or coarse sand on top; this 
merges into finer sand and this again finally into a bed of clay. 

Rocks, however, are very complex in their composition, and 
sands contain most of the elements of the rocks of which they are 
fragments. For this reason molding sands in different parts of the 
United States vary considerably. 

A good molding sand first of all, should be refractory, that is, 
capable of withstanding the heat of molten metal. It should be 
porous to allow the escape of gases from the mold. It should have 
a certain amoimt of clay to give it bond or strength, and should have 
an even grain. All of these properties will vary according to the 
class of work for which the sand is used. 

Elements. The two important chemical elements in such sands 
are silica, which is the heat-resisting element, and alumina, or clay, 
which gives the bond. Other elements which are found in the mold- 
ing sands are oxide of iron, oxide of lime, lime carbonate, soda potash, 
combined water, etc. The analyses shown in Table I, made by 



FOUNDRY WORK 5 

W. G. Scott, give an idea of tlie proportions of these elements in the 
different foundry sands. 

Silica alone is a fire-resisting element, but it has no bond. These 
other elements help in forming the bond. But under heat, silica 
combines and fuses with them, forming silicates. These silicates 
melt at a much lower temperature than does free silica. Therefore 
with sands carrying much limestone in their make up, or with those 
containing much oxide of iron, soda potash, etc., the molten iron will 
burn in more, making it more difficult to clean the casings. 

The limestone combinations also go to pieces under heat, tending 
to make the sand crumble, which may result in dirty castings. 

The proportions given in Table I must not be considered as 
absolutely fixed, for no two samples of sand, even from the same bed, 
will analyze exactly alike. The table is instructive, however, 
because it indicates the reasons why the different sands are especially 
adapted to the use to which they are put in practice. 

Fire Sand. Such sand is used in the daubing mixture for repair- 
ing inside of cupola and ladles, and should be in the highest degree 
refractory, and should contain as little matter as possible that would 
tend to make it fuse or melt. 

Light Molding Sand. This sand is used for castings such as 
stove plate, etc., which may have very finely carved detail on their 
surfaces, but are thin. The sand should be very fine to bring out 
this detail; it must be strong, i.e., high in clay, so that the mold will 
retain every detail as the metal rushes in. On the other hand, the 
work will cool so quickly that after the initial escape of the air and 
steam there will be very little gas to come off through the sand. 

Medium Sand. Sand of this grade is used in bench work and 
light floor work, for making machinery castings having from J- to 
2-inch sections. These will have less fine detail, so the sand may be 
coarser than in the previous case. The bond should still be fairly 
strong to preserve the shape of the mold, but the tendency of the 
large proportion of clay to choke the vent will be offset by the larger 
size of the grain. This vent must be provided for because the metal 
will remain hot in the mold for a longer time and will cause gases to 
form during the whole of its cooling period. 

Heavy Sand. This grade of sand is used for the largest iron 
castings. Here the sand must be high in silica and the grain coarse. 



6 FOUNDRY WORK 

because the heat of the molten metal must be resisted by the sand, 
and gases must be carried off through the sand for a very long time 
after pouring. The amount of bond or clay must be small or it will 
cause the sand to cake and choke these gases. The detail is gener- 
ally so large that the lack of bond is compensated for by the use of 
gaggers, nails, etc. The coarse grain is rendered smooth on the 
mold surface by careful slicking. 

Core Sand. Core sand, often almost entirely surrounded by 
metal, must be quite refractory but have very little clay bond. 
This bond would make the sand cake, choking the vent, and render 
it difficult of removal from a cavity when cleaning the casting. 
Compared with medium molding sand, it shows higher in silica, 
although having less than half the proportion of alumina. 

Free Sands. Sands having practically no clay in them are 
called free sands. Of these there are two kinds in use: river sands, 
and beach sands. 

River Sand. The grains of river sand retain the sharp frac- 
tured appearance of chipped rock, and these little sharp grains help 
much in making a strong core because the sharp angular grains 
interlock one with another. River sand is used on the larger 
core work. 

Beach Sand. Beach sand is considerably used in coast sections 
because it is relatively inexpensive, but its grains are all rounded 
smooth by the incessant action of the waves. It will pack together 
only as will so many minute marbles. For this reason it is used 
only for small cores. 

Facings 

Function. Foundry facing is the term given to materials 
applied to or mixed with the sand which comes in contact with 
the melted metal. The object is to give a smooth surface to the 
casting. They accomplish this in two ways: (1) by filling in the 
pores between the sand, thus giving a smooth surface to the mold 
face before the metal is poured; and (2) by burning very slowly 
under the heat of the metal, forming a thin film of gas between the 
sand and iron during the cooling process. This prevents the iron 
burning into the sand and causes the sand to separate from the 
casting when cold. 



FOUNDRY WORK 7 

Different forms of carbon are used for this purpose because 
carbon will glow and give off gases, but it will not melt. The prin- 
cipal facings are graphite, charcoal, and sea coal. 

Graphite. Graphite is a mineral form of carbon. It is mined 
from the earth and shipped in lumps which are blacker than coal 
and are soft and greasy like a lump of clay. The purest graphite 
comes from the Island of Ceylon, India. There are several beds, 
however, in the coal fields of North America. 

Charcoal. Charcoal is a vegetable form of carbon. It is made 
by forming a shapely pile of wood, covering this over with earth and 
sod, with the exception of four small openings at the bottom and one 
at the top. The pile is set on fire and the wood smoulders for days. 
This burns off the gases from the wood, leaving the fibrous structure 
charred but not consumed. Charcoal burning is done in the lumber- 
ing districts. The charcoal for foundry facings should be made 
from hard wood. 

Sea Coal. Although sea coal contains a high per cent of car- 
bon, it is less pure than the other facings and gives off much more 
gas. Sea coal is made from the screenings from the soft-coal 
breakers. The coal should be carefully selected by the manu- 
facturer and be free from slate and very low in sulphur. 

Distinction. All facings are manufactured by putting the 
raw materials through a series of crushers, tumbling mills, or old- 
fashioned burr stone mills, and then screening them. The finest 
facings are bolted much as flour is. 

In the shop the molder distinguishes between facings or black- 
ings, and facing sand. Blacking consists of graphite or charcoal, 
and is applied to the finished surface of a mold or core. Facing sand 
is the name given to a mixture of new sand, old sand, and sea coal, 
which in the heavier classes of work forms the first layer of sand next 
the pattern. 

The use of the different facings will be clearly seen from the 
tabulation on page 8. 

Miscellaneous Materials 

Fire Clay. Fire clay comes from the same source that sand 
does. It is almost pure oxide of alumina, which is separated out 
from the sand by a combination of the chemical action of the waters 
of the streams. Fire clay has traces of the other impurities men- 



FOUNDRY WORK 



Characteristics of Facings 



Material 


Uses 


Action 


Charcoal 


Good facing for light molds; dusted 
on from bag after pattern is drawn. 

Mixed with molasses water for 
wash for small cores and dry-sand 
work. 

Mixed with some graphite and clay 
wash for blacking for heavy dry-sand 
and loam work; slicked over with 
tools. 

May be used as a parting dust on 
joint of bench molds. 


Burns at low enough 
temperature to be effec- 
tive before thin work 
cools. 

Resists moisture ; pre- 
vents sand surfaces from 
sticking together. 


Graphite 


Good facing for bench molds; dusted 
on from bag; good for medium and 
heavy green-sand work. Applied with 
camel's hair brush, and slicked over 
with tools. 

As heavy blacking for dry-sand and 
loam work, used as above. 


Good on heavier green 
sand because it is more 
refractory than char- 
coal, but still forms gas 
enough to keep metal 
from burning into sand. 


Sea Coal 


Mixed with facing sand in propor- 
tions from 1 : 6 to 1 : 12. See section on 
Molding. 


Helps to force vents 
through sand when mold 
is first poured, and pre- 
vents strong sand of the 
facing from caking, be- 
cause it continues to 
throw off gas after cast- 
ing has solidified. 



tioned in the analysis of molding sands. It is found in the lowest 
strata of the deposit beds. It is used to mix with fire sand in the 
proportion of 1 to 4 as the daubing mixture for cupola and ladles. 

Clay wash is a mixture of fire clay and w^ater. The test for 
mixing it is to dip the finger into the wash and then withdraw it, 
whereupon there should be an even film of clay deposited on the 
finger. Clay wash is used as the basis of heavy blackings. It is 
used as follows: for wetting crossbars of flasks; for breaks in sand 
where a repair is to be made; to wet up the dry edges of ladle linings 
when repairing with fresh daubing mixture; in fact, any place where 
a strong bond is required at some particular spot. 

Parting Dusts. Parting sands or parting dusts must contain no 
bond. They are used to throw on to the damp surfaces of molds 
which must separate one from another. They prevent these sur- 
faces formed of high bond sands from sticking to each other. 



FOUNDRY WORK 9 

The cheapest parting sand, and by far the most commonly used, 
is obtained by putting some burnt core sand, from the cleaning shed, 
through a fine sieve. 

Beach sand is also used as a parting sand, but the rounded 
nature of its grain weakens the molding sands more than does burnt 
core sand. 

Charcoal facing dusted from a bag makes an excellent parting 
dust on fine work. 

A dust manufactured expressly for the purpose and called "Par- 
tainol" is the most perfect material for fine work. This is applied 
from a dust bag. It is not only useful for sand joints, but is a great 
help if there is a deep lift on a pattern where the sand is liable to 
stick, or for a troublesome box in the core room. 

Core Binders. Although the materials for this purpose — flour, 
rosin, oil, etc. — are on the purchasing list of the general foundry 
buyer, for the purposes of this article they will be explained in detail 
under Core Work. 

TOOLS 

Under this heading only the hand tools and equipment used by 
the molder in putting up his mold are described. The mechanical 
appliances for reducing labor are described in a later section. 

Flasks. To use sand economically for molds, sets of open frames 
called flasks are used. Flasks consist of two or more such boxes. 
The lower box is called the drag or nowel, the upper box is called the 
cope. If there are intermediate parts to the flask they are called 
cheeks. Flasks are fitted with pins and sockets so that they will 
always register. 

Snap Flask. For small castings the molds are rammed up on 
benches or projecting brackets. Such work is termed bench work and 
the flasks are usually what are known as snap flasks. They range in 
size from 9 by 12 inches to 18 by 20 inches. As is seen in Fig. 1, 
these flasks hinge on one corner and have catches on the diagonal 
corner. The advantage of the snap flask is that any number of 
molds may be put up with but one flask, and the flask removed as 
each mold is completed. There are several good snap flasks to be 
had on the market. Many foundries, however, make up their own. 

Each size of flask should have at least one smooth straight board 
called the mold board, the size of outside dimensions of the flask. 



10 



FOUNDRY WORK 




Rough boards or bottom boards of same size should be provided, 

one for each mold that will be put up in a day. 

Boards for snap work are made of from |- to 1-inch stuff, and 

should have two stiff cleats, as shown in Fig. 2, to hold them straight. 

Wood Flask. For 

heavier castings where the 

molds are made on the 

floor, box flasks are used 

raade of wood or iron. 

In the jobbing shop, 

wood flasks are more 

economical, as they can 

more readily be altered to 

fit a variety of patterns, 

while in a foundry turn- 
Fig. i. Snap Flask '^^^ ^^^^ ^ ^^^^^^^ jj^^ ^f 

castings, iron flasks pay because they require less repair. 

Wooden flasks of necessity receive hard usage in the shop and 
grow weaker each time they are used. They will burn more or less 
each heat; they receive rough usage when the mold is shaken out; and 
often the flasks must be stored where they are exposed to all kinds of 
weather. It is economy, therefore, to build w^ooden flasks heavier 
than would be necessary if they were always to be used in their new 
condition. 

Fig. 3 shows the construction of a typical wooden flask; the sides 
project to form lifting handles; the ends are gained in to the sides. 
Through bolts, in addition to the nailing, hold the sides firmly. A 

detail of the pin is shown at A, 
and at -S is a cast-iron rocker 
useful on flasks over 4 by 5 feet, 
to facilitate lifting and rolling 
over. The cleats make it a simple 
matter to alter crossbars. The 
crossbars should be not over 8 
inches on centers. For more than 3-foot spans they should have short 
crossbars through the middle connecting the long ones. In flasks 4 
feet and over there should be one or more iron crossbars and a J-inch 
through bolt with good washers to clamp the sides firmly to them. 




Fig. 2. Mold Board 



FOUNDRY WORK 



11 



TABLE II 
Sizes of Wooden Flasks 



Flask Sizes 
(6 inches deep) 


Material '] 


Sizes 


Arrangement 


Sides 
(inches) 


Cross- 
bars 
(inches) 


Short 
Cross- 
bars 
(rows) 


Iron 
Cross- 
bars 
(number^ 


Up to 24 by 24 in. 
18 in. to 24 in. wide up to 5 ft. long 
24 in. to 36 in. wide up to 6 ft. long 
36 in. to 48 in. wide up to 7 ft. long 


13^2 

2 

3 


1 
1 

IM 


1 

2 


1 

2 

2 



Note. For each additional 6-inch depth of cope or drag add 25 per cent to the thick- 
ness given. 

Tiible II shows thickness of stuff for sides and crossbars for 
average sizes of jobbing flasks. 

Illustrative Example. Find thickness of sides and bars in a 
flask 30 by 48 inches. 

By referring to Table II, it is noted that for lengths on the sides 
over 2 feet and under 5 feet the thickness of sides should be 2 inches. 




Wooden Flask 



Similarly, for widths of flask of over 24 inches and under 36 inches, 
the thickness of crossbars should be IJ inches. 



12 



FOUNDRY WORK 



Iron Flash, In Fig. 4 is shown the construction of a large iron 
flask suitable for dry-sand work. The pieces of the flask are usually 
cast in open sand from a skeleton pattern, all holes cored in. The 
crossbars are cast in the same way; they have a slot in the flange 
instead of holes to facilitate adjusting them. Trunnions and rockers 
are sometimes cast on the sides in a core instead of being made 
separate and bolted on. Holes for pins are usually drilled through 
the joint flange. For pins, short iron bars are used temporarily in 



izn^ 



fiJ i r^ 



A 



\ \ C-j!'^^ I 



N. 



J^ 



^ r— -^-g^-i I r- —n r-Tj^T—-^. pi 



P 




Tr union 







Fig. 4. Iron Flask 



closing. The thickness of metal varies from | inch to li inches, 
according to size of flask. 

In Fig. 5 is shown a typical form of iron flask used on some 
molding machines. The boxes are cast in one piece. The handles 
serve as lugs for the closing pins. Only one pin is fixed on each box. 
This makes the boxes mterchangeable and capable of being used for 
either cope or drag. 

Shovel. For cutting and handling loose sand the molder uses 
a shovel with flat blade, as in Fig. 6, for it is often more convenient 
to let the sand slide off of the side of the shovel than off of the end. 



FOUNDRY WORK 



13 



This is especially true when shoveling sand into bench molds or 
molding-machine flasks. 

Sieve, The foundry sieve or riddle, Fig. 7, is used to break up 
and remove lumps, shot iron, 
nails, etc., from the sand 
placed next the pattern or 
joint. Sieves should have 
oak rims with brass or 
galvanized-iron wire cloth. 
In ordering, the diameter 
of rim and the number of 
meshes to ,the inch of the 
woven wire is given. Good 

« . 1 . /? 1 Fig. 5. Flask for Molding Machine 

Sizes tor the iron loundry 

are 16 inches to 18 inches diameter. No. 8 to 12 on bench work, 

No. 4 to 8 on floor work. 

Rammers. Rammers are used for evenly 
and quickly packing the sand in the flask. One 
end is in the shape of a dull wedge, called the 
peen end, the other is round and flat called the 
butt end. Of the rammers shown in Fig. 8, a is 
the type used on bench work; 6 is a floor rammer 
having cast heads and wooden shaft; c shows a 
rammer made up in the foundry by casting the 






Fig. 6. Flat Blade 
Shovel 



Fig. 7. Foundry Sieve 



heads on the ends of an iron bar; d shows a small peen cast on a 
short rod — this is convenient for getting into corners or pockets on 
floor work. 



14 



FOUNDRY WORK 



Pneumatic Type. In shops equipped with compressed air a 
pneumatic rammer, as shown in Fig. 9, is sometimes used to butt 
off large flasks, and for ramming loam molds in pits. 

Finishing Tools. Holders' tools are designed for shaping and 
slicking the joint surfaces of a mold and for finishing the faces of the 
mold itself. Excepting the trowels, they are forged in one piece 




Fig. 8. Rammers 



Fig. 9. Pneumatic Rammers 



from steel. The trowels have steel blades and short round handles 
which fit conveniently mto the grasp of the hand. All of the tools 
are ground slightly crowning on the bottom, and they are rocked 
just a little as they are worked back and forth over the sand to pre- 
vent the forward edge cutting into the surface of the mold. 

Of the sixty or more combinations of shapes on the market, 
the few illustrated represent the ones most commonly used in job- 
bing shops. 



FOUNDRY WORK 



15 



Trowels. Trowels, Fig. 10, are used for shaping and smoothing 
the larger surfaces of a mold. The square trowel a is convenient for 
working up into a square corner, and the finishing trowels b and c 




(c) 

Fig. 10. Trowels 



Fig. 11. Slicks 



are more for coping out and finishing along the curved edges of a 
pattern. Trowels are measured by the width and length of blade. 

Slicks. Slicks are designated by the shape of the blade and the 
width of the widest blade. In Fig. 11, a is a heart and leaf; 6 is a 




leaf and spoon; c is a heart and square; and dis a spoon and bead. 
These are in sizes of 1 inch to If inches. They are used for repairing 
and slicking small surfaces. 

Lifters. Fig. 12 shows lifters used to clean and finish the 
bottom and sides of deep narrow openings; a is a floor lifter, made in 



16 



FOUNDRY WORK 



sizes from J- by lO-inch to 1- by 20-mch; 6 is a bench lifter, the 

sizes of which vary from -^ inch to | inch wide. 

Corner Slicks. Fig. 13 
shows at a and b inside and 
outside square-corner sUcks, 
made in sizes of 1 to 3 inches; 
c is a half-round corner, 





Fig. 13. Square Corner Slicks 




Fig. 14. Floor Swab 



widths 1 inch to 24 inches; 
and (Z is a pipe slick made 1 
inch to 2 inches. This style 
of tool is mainly used on dry 
sand and loam work. 

Swabs. Swabs are used 
to moisten the edges of the 
sand about a pattern before 
drawing it from the mold. 
This foundry swab is a dan- 
gerous though useful tool. 
Its danger lies in the too free 
use of water around the mold, which may result in blow- 
holes. A good swab for bench work is made by fasten- 
ing a piece of sponge, about double the size of an egg, to 
a goose quill or even a pointed hardwood stick. The 
point will act as a guide and the water may be made 
to run or simply drop from the point by varying the 
pressure on the sponge. 

Floor swabs. Fig. 14, are made from hemp fiber. 
They should have a good body of fiber shaped to a 
point, and should be made about 12 inches or 14 inches 
long. They will take up considerable w^ater and deliver 
it from the tip of the point. In heavy work the swab 
is trailed lightly over the sand like a long bristled brush. 
Vent Rods. Vent wires are used to pierce small 
Fig. 15. Vent bolcs through the sand connecting the mold cavity with 
^"'^ the outside air. For bench work a knitting needle is the 
most convenient thing to use. It should have a short hardwood 
handle or cast ball on one end. Select a needle as small as possible, 
so long as it will not bend when using it. 



^ 



FOUNDRY WORK 



17 



Heavy vent rods are best made, as shown in Fig. 15, of a spring 
steel from -5^ inch to i inch with the pointed end enlarged a little 
to give clearance for the body of the 
rod when run deep into the sand. 

Draw Sticks, Draw sticks are 
used to rap and draw patterns 
from the sand. In Fig. 1 6 are shown 
three kinds: a is a small pointed rod 
J inch to f inch in size, which gets 
its hold by simply driving it into 
the wood of the pattern; & is a wood 
screw welded to an eye for conven- 
ience; c is an eye rod with ma- 
chine-screw thread, which requires 
a metal plate let into the pattern. 
The plate is called a rapping plate 
and is made with separate holes 
not threaded, into which a pointed 
rapping bar is placed when rapping 
the pattern, thus preserving the 
threads used for the drawbar. 

Clamps. In pouring, the parts 
of a mold must be clamped by 
some method to prevent the pres- 
sure of the liquid metal from sep- 
arating them, causing a run-out. For light work a weight such as 
shown in Fig. 17 is the most convenient. This is simply a plate of 
cast iron 1 inch to 1| inches thick, with a cross-shaped opening 
cast in it to give considerable 
liberty in placing the runner in 
the mold. The weights are 
from 15 to 40 pounds, accord- 
ing to size of flasks. 

Floor flasks are fastened 
with clamps made of cast iron 
which are tightened by prying them on to a hardwood wedge. In 
Fig. 18 is shown how the wedge may first be entered and how the 
clamping bar is used to firmly clamp the flask. For iron flasks 




Fig. 16. Draw Sticks 




Fig. 17. Weight 




Clamp Wedq^ 

Fig. 18. Illustrating Method of Clamping 



18 FOUNDRY WORK 

used in dry-sand work the clamps are very short, as only the flanges 
are clamped together, as may be seen in Fig. 4. In that connection 
iron wedges are used instead of wood. Often the iron bottom board 

is clamped on and the joint 
flanges bolted together before 
pouring. 

MOLDING PROCESSES 

PRINCIPLES OF QREEN= 
SAND MOLDING! 

Good Work. There are 
certain principles underlying 
iron molding which hold good 
in all classes of founding, 
and a practical understand- 
ing of these principles is necessary for good work in any line. 

Aside from the fact that generally a mold is wanted which takes 
the least possible time to put up, three things aimed at in green- 
sand work are: (1) a sound casting, which is free from internal 
imperfections, such as blow holes, porous spots, shrinkage cracks, 
etc.; (2) a clean casting, which is free from dirt, such as slag, sand, 
etc.; and (3) a smooth casting, having a uniform surface free from 
scabs, buckles, cold-shuts, or swells. 

Sand Mixture. The natural sands best adapted to obtain 
these results have already been dealt with. The methods of adding 
new sands vary with different classes of work. For light work the 
entire heap should be kept in good condition by adding a little new 
sand every day, for the light castings do not burn out the sand to 
a great extent. 

On heavier w^orK of 50 pounds and upward, the proportion of 
sand next the pattern is so small compared with that used simply 
to fill the flask, that it does not pay to keep the entire heap strong 
enough for actual facing. The heap should be freshened occasionally 
with a cheap molding sand, but for that portion of the mold w^hich 
forms the joint surface, and especially that which comes in contact 
with the metal, a facing sand should be used. 

The range of new sand in facing mixtures on a 10-part basis, 
with sea coal in addition, is as tabulated herewith: 



FOUNDRY WORK 
Proportions of Facing Mixtures 

(Basis of 10 Parts) 



19 



Sand 


Sea Coal 
(additional part) 


New 


Old 


Free 


3—6 


6—2 


1—2 


i-l 



These proportions, and the thickness of the layer of facing sand, 
vary with the weight of metal in the casting. Too much new sand 
tends to choke the vent and to cause sand to cake; too little new 
sand renders facing liable to cut or scab. Too much sea coal makes 
sand brittle and more difficult to work, and also gives off too much 
gas which is liable to cause blowholes in casting. Not enough 
sea coal allows the sand to cake, making cleaning difficult. 

Tem'pering and Cutting, To prepare foundry sand for making 
a mold, it must be tempered and cut through. This is now usually 
done by laborers. To temper the sand, throw water over the heap 
in the form of a sheet by giving a peculiar backward swing to the 
pail as the water leaves it. Then cut the pile through, a shovelful 
at a time, letting the air through the sand and breaking up the lumps. 
This moistens the clay in the sand, making it adhesive and puts 
the pile in the best condition for working. 

To test the temper, give one squeeze to a handful of sand. 
An excess of water will at once be detected by the soggy feeling 
of the sand. Now hold the egg-shaped lump between thumb and 
finger of each hand and break it in the middle. The edges of the 
break should remain firm and not crumble. Too much moisture 
will make excess of steam in the mold, causing blowholes. Not 
enough moisture renders sand weak and apt to wash or cut. 

Bearing in mind the nature of the materials we have to work 
with, we must now study the important operations involved in 
making a sand mold. 

Sifting. The sand next to the joint and over the pattern 
should be sifted. The thickness of this layer of sifted sand varies 
from about f inch for light work to 2 inches on very heavy work. 
The fineness of the sieve used depends upon the class of work. No. 
16 or 12 would be used for small name plates, stove plate, etc., while 



20 



FOUNDRY WORK 



No. 8 or 6 is good for general machinery work. On floor work, 
from 4 to 6 inches of sand back of the facing should be riddled through 
a No. 4 sieve to ensure more even ramming and venting. 

Ramming. The object of ramming is to make the sand hang 
into the flask and to support the walls of the mold against the flow 
and pressure of the metal. The knack of ramming just right only 




Fig. 19. Setting Gaggers 



comes with continued practice and comparison of results. Hard 
ramming closes up the vent, causing blowholes. Iron will not 
*'lay'' into a hard surface. Soft ramming leaves a weak mold sur- 
face, and the flow of the metal as it enters the mold washes or cuts 
the sand, leaving a scab on one part of the casting and sand holes 
on another. A mold rammed too soft tends to swell under the 
pressure of the liquid metal, making the casting larger than the 



pattern or leaving an unsightly lump on the casting. The bottom 
parts of a mold, being under greater casting pressure, must be 
rammed somewhat harder than the upper portions. The joint 
also should be packed firmly, as it is exposed to more handling than 
any other part. 

Gaggers, Crossbars are put in the cope to make it possible 
to lift the sand with the cope without excessively hard ramming. 
As an additional support for the cope sand on large work there are 






Fig. 20. Chaplets 

used gaggers, which are L-shaped pieces of iron made from wrought 
or cast iron of from 3^-inch to J-inch square section. 

The force of sand pressing against the long leg of the gagger 
holds it in place and the short leg supports the sand about it. There- 
fore the gagger will hold best when the long leg is placed tight against 
the crossbar and is plumb. The long leg of the gagger should not 
project above the level of the cope, as there is much danger of striking 
it and breaking in the mold after the flask is closed. In Fig. 19 
are shown the right and wrong ways of setting gaggers. 

Use of Chaplets. Chaplets should be used to support parts 
of cores which cannot be entirely secured by their prints which are 
held in the sand of the mold. In Fig. 20 are shown the three prin- 
cipal forms of chaplets used, and how they are set in the mold; 
a is a stem chaplet; 6 is a double-headed or stud chaplet; and c is 
a form of chaplet made up of strip metal. 



22 



FOUNDRY WORK 



That portion of the chaplets which is to be bedded in metal 
is tinned to preserve it from rusting, because rusty iron will cause 
liquid metal to blow. For small cores nails are often employed 
for this purpose, but only new ones should be used. With the stem 
chaplets the tails must be cut off when the casting is cleaned — the 
stud chaplet becomes entirely embedded in the metal. There are 
now manufactured and on the market many different styles of 
chaplets. In selecting the size and form for a given purpose the head 
of the chaplet should be large enough to support the weight of the 

core without crushing into the 
sand and thin enough to fuse 
into the liquid metal. The stem 
must be small enough to fuse 
well to the metal and stiff enough, 
when hot, not to bend under its 
load. 

Venting. In the section on 
Sands reference has already been 
made to gases which must be 
taken off from a mold when it is 
poured. There are three forms 
of these: (1) air, with which the 
mold cavity is filled before pour- 
ing; (2) steam, formed by the 
action of the hot metal against 
the damp sand during the pour- 
ing process; and (3) gases formed 
while the casting is cooling, from 
chemical reactions within the liquid metal and from the burning 
of organic matter, facings, core binder, etc., m the sands of the 
mold. It is of the greatest importance that these gases pass off 
quickly and as completely as possible. If they do not find free 
escape through the mold they are forced back into the liquid 
metal, making it boil or blow. This may blow the metal out 
through risers and runners, or simply form numerous little bubble- 
shaped cavities in the casting, called blowholes. These often form 
just below the skin of the casting and are not discovered until 
the piece is partially finished. 




Fig. 21. Use of Risers 



FOUNDRY WORK 



23 



Various Systems. One cannot depend entirely upon the 
porosity of the molding sands, but must provide channels or vents 
for the escape of these gases. For light work a free use of the vent 
wire through the sand in the cope will answer all purposes. 

On castings of medium weight, besides venting with the wire, 
risers are placed directly on the casting or just off to one side as 
shown in Figs. 19 and 21. These are left open when the mold is 
poured and provide mainly for the escape of the air from the mold. 

Heavy castings that will take time to cool, and thus keep 
facings burning for a long time after the mold is poured, require 
venting on sides and bottom as 
well as top. Fig. 21 shows side 
vents aaaa connecting with the 
air through the channel bbb cut 
along joint and risers ccc passing 
through the cope. At tKe bottom 
the vents connect with cross-vents 
dd run from side to side between 
the bottom board and edge of 
flask. Fig. 22 shows a mold 
bedded in the floor; the side or 
down vents connect at the top, as 
in previous examples, and at the 
bottom with a cinder bed about 
2 inches thick, rammed over 
entire bottom of pit. The gases find escape from this cinder bed 
through a large gas pipe. 

Action During Pouring. In pouring, the gas from vents should 
be lighted as soon as may be. The burning at the mouths of vents 
helps to draw the gases from below and also keeps the poisonous 
gas out of the shop. 

It is customary to keep risers closed with small cover plates 
when large castings are being poured so that the air in the mold 
will be compressed as the metal rises in the mold. This helps 
sustain the walls of the mold and forces the vents clear so that they 
will act more quickly when the mold is full. These covers are 
removed occasionally to watch the progress of pouring, and are 
entirely removed when the metal enters the risers. 




Fig. 22. Mold Bedded in Floor 



24 



FOUNDRY WORK 



Gating. Gating is the term applied to the methods of forming 
openings and channels in the sand by which liquid metal may- 
enter the mold cavity. The terms sprues and runners are also 
used in the same connection in some shops. 

Functions of Parts. There are practically three parts to all 
gates: pouring basin; runners; and gate, as seen in Fig. 21. The 
runner is formed by a wooden gate plug made for the purpose. The 
pouring basin is shaped by hand on top of the cope, and the gate 
proper is cut along the joint surface by means of a gate cutter. 
In all cases the gate section should be smaller than any other part 
so that, when pouring, the runner and basin may be quickly flooded; 
also that the gate when cold will break off close to the casting and 

lessen the work of cleaning. 

The object of gating is to fill the mold 
cavity with clean metal — to fill it quickly, 
and while filling, to create as little dis- 
turbance as possible in the metal. 

The impurities in liquid metal are 
lighter than the metal itself, and they 
always rise to the top when the melted 
metal is at rest or nearly so. Advantage 
is taken of this important property 
to accomplish the first of the objects 
mentioned. 

Fig 23 shows a good type of gate 
to use on light work. For reasons given, 
the point a should have the smallest sectional area. This section 
should be wider than it is deep as shown at 6, because the hot iron 
necessary for light work runs very fluid. 

The runner should not be more than f to f inch in diameter. 
The pouring basin should be made deepest at point c, and slant 
upward crossing the runner. When pouring, the stream from the 
ladle should enter at c, flood the basin at once, and keep it in this 
condition. The current of the metal will then tend to hold back 
the slag, allowing clean metal to flow down the runner. 

Shimming Gate. When particularly clean castings of medium 
weight are required, some form of skimming gate should be used. 
Fig. 24 illustrates one of several practical forms. They all depend 




Fig. 23. Gate 



FOUNDRY WORK 



25 





fj 



for their efficiency upon the principle cited. In the illustration, 
a is the pouring basin' and runner, 6 is a good sized riser placed 
about 3 or 4 inches from a, and c is a channel cut in the cope joint, 
connecting these two. The gate d should be cut in the drag side 
of the joint, just under the riser but at a right angle with the 
direction of c. The metal rushing down the runner is checked by 
the small size of the gate and so washes any dirt or slag up into 
the large riser h. The level of metal in this riser must be sustained 
by sufficiently rapid pouring 
until the mold is filled. 

■ In bench work and floor 
work, the greatest care must 
be used to have all parts of 
the gate absolutely free from 
loose sand or facing which 
would wash into the mold 
with the first flood of metal. 

On heavy work special 
skimming gates are not used, 
for the capacity of the pour- 
ing basin is very much 
greater than that of the run- 
ners which can be quickly 
flooded and thus retain the 
slag. Besides this, large 
risers are set at the sides 
or directly upon the casting, to receive any loose sand or facing 
that washes up as the mold is being filled. Fig. 22 illustrates 
this type. 

Important Conditions. As regards the filling of the mold 
quickly and quietly, these two conditions are closely allied. The 
shape and thickness of the casting are the important factors in 
determining the number and position of the gates. Aside from 
the fact that the gate should never be heavier than the part of the 
casting to which it attaches, the actual size of the gate opening 
is something that the molder must learn from experience. 

In arranging gates with regard to the shape of the pattern, 
the following points should be borne in mind: Place gates where 




Fig. 24. Skimming Gate 



26 



FOUNDRY WORK 



CD 




Fig. 25. Use of Gates 



the natural flow of the metal will tend to fill the mold quickly. 
Usually gate on the lighter sections of the casting. Select such 
points on the casting that the gates may be 
broken and ground off with least trouble — the 
greater the number of castings to be handled, 
the more important this point becomes. A 
study of the molding problems given will illus- 
trate this point. 

Provide enough gates to fill all parts of 

\ I the mold with metal of uniform temperature. 

This depends upon the thickness of the work, 
as is illustrated in Fig. 25 by two molds having 
the same shape at the joints but of different 
thicknesses. In thin castings the metal tends 

r~7 \ ^ —^ / "to chill quickly, so it must be well distrib- 

M__ I uted. In this illustration, a is a plate J inch 

^ / thick, and should have several gates. |A piece 

having the same diameter but heavier, would 
run better from one gate as at b, while if a bush- 
ing of this diameter is required, the best results 
would be obtained by gating near the bottom, as in 
Fig. 22. For running work at the bottom as shown 
in Fig. 22, the gate piece h is separate from the run- 
ner, and is slicked into the mold after the pattern 
is drawn. The runner r should extend below 
the level of the gate to receive the force of the 
first fall of metal, which otherwise would tend 
to cut the sand of the gate. 

Shrinkage Heads, Melted metal shrinks 
as it cools, and this process begins from the 
moment the mold is filled. The surfaces 
next to the damp sand are the first to solidify, 
and they draw to themselves the more fluid 
metal from the interior. This process goes 
on until the whole casting has solidified. 
This shrinkage causes the grain in the middle 
to be coarse and sometimes even open or porous. 

The lower parts of a casting are under the pressure or weight 




Fig. 26. Sinking 
of Casting 




Fig. 27. Feeding Rod 



FOUNDRY WORK 



27 



a 




c 






< 













a. 


cr e 




^ 




/ 











of all the metal above, and so resist these shrinkage strains. The 
top parts, however, require the pressure of liquid metal in gates 
or risers to sustain them until they have hardened sufficiently to 
hold their shape, or they will sink as indicated by the section, Fig. 26. 
Risers, mentioned in connection with securing clean metal, are also 
required on heavy pieces to prevent this distortion and to give sound 
metal. When used in this way they are called shrinkage heads 
or feeders. They should be 6 or 8 inches in diameter, so as to keep 
the iron liquid as long as possible, and should have a neck 2 or 3 
inches in diameter, to 
reduce the labor required 
to break them from the 
casting in cleaning. To 
prevent the metal in 
this neck from freez- 
ing, an iron feeding 
rod is inserted, as in 
Fig. 27, and is churned 
slowly up and down. 
This insures fluid metal 
reaching the interior. As 
the level in the feeder low- 
ers, hot metal should be 
added from a hand ladle. 
Pressure in Molds. 
The subject of the pres- 
sure of liquid iron men- 
tioned repeatedly in the 
foregoing pages, must be 
dealt with by the molder, in weighting his copes, strengthening flasks, 
securing cores, etc., and most frequently in connection with the first- 
of these. 

Natural Laws. Molten iron acts in accordance with the same 
natural laws that govern all liquids — as, for example, water (see 
Mechanics, Part II); iron, however, is 7.2 times heavier than water. 
The two laws applicable in foundry work are these : (1) Liquids 
always seek their own level; (2) pressure in liquids is exerted in every 
direction. 



A 
c 






a 


c 


< 


? 




Hill 
4-f4- 

^ 1 1 i ! 


f 

















Fig. 28. Illustrating Pressure of Liquids in Molds 



28 



FOUNDRY WORK 



Pressure- Head Example. Applying the first law, if we have 
two columns of liquid iron connected at the bottom, they would 
just balance each other. For convenience we shall leave out of our 
calculations the upward pressure on the gates in the following 
examples, for in practical work they need seldom be taken into 
account. 

In A, Fig. 28, suppose these columns stand 6 inches above 
the joint bd, and that the column cd, has an area of 1 square inch. 
In B, suppose the area of the right-hand column cdef is 5 times 
the area of column cd. In both cases the level with top of runner 
a will be maintained. The depth of the cavity below the joint 

hdf makes no difference in main- 
taining these levels. The weight 
of one cubic inch of iron, .26 
pound, is taken as the basis of 
all calculations. 

Now if we close the column 
cd at d, as in C, it is clear that 
it would require the actual 
weight of that column to balance 
the lifting pressure of the surface 
d, or 6X.26Xl = 1.56 pounds. 
And if the larger area df is closed 
over, as in D, it takes 5 times 
this .weight to resist the pressure 
exerted upon it by the runner, 
or 6X. 26X5 = 7.8 pounds. If the pattern projected 2 inches into 
the cope, the height of the runner above the surface acting 
against the cope would be 4 inches, and the pressure to be overcome 
would be equal to the weight of cghe, or 4 X .26 X 5 = 5.2 pounds. 

The important factors, then, are: height of runner; and area 
of mold which presses against the cope. We can therefore state 
a rule: To calculate the upward pressure of molten iron, multiply 
the depth in inches hy the weight of one cubic inch of iron {.26), and 
multiply this product by the area in square inches upon which the 
pressure acts, 

Pressure-Distribution Example. Applying the second law cited, 
the strains on sides and bottom of molds and upon cores is explained. 





7 


1 7 


i' 1- 


?" 

e 






I 










c^ 











Fig. 29. Diagram Showing Analy.sis of 
Liquid Pressure 



FOUNDRY WORK 29 

By the rule just stated we first find the pressure per square 
inch at any given level by multiplying the depth by .26, and it is 
obvious that this pressure increases, the lower in the mold a point 
is taken. 

In Fig. 29, the pressure at a equals Ax.26. This also acts 
against the sides at ee. The pressure at b is h'X .26, and is exerted 
sidewise and downward. The pressure at c is A"X.26. This 
point, being half way between the levels a and b, represents the 
average sidewise or lateral pressure on all of the sides. 

If this mold, then, is 11 inches square and 9 inches deep, with the 
pouring basin 6 inches above the joint, we have the following con- 
ditions; ^ 

Area of a = 121 sq. in. 

Area of 6 = 121 sq. in. 

Area of c (one side) = 99 sq. in. 

Area of four sides =396 sq. in. 

Height of A = 6 in.; pressure head = 1.56 lb. per sq. in. 

Height of A' =15 in.; pressure head = 3.90 lb. per sq. in. 

Height of /i" = 10| in.; pressure head = 2.73 lb. per sq. in. 

Multiplying these together, we have the pressures on the various 
faces as follows: 

Upward pressure on a = 188.76 lb. 

Total pressure on side c — 270.27 lb. 

Total pressure on four sides = 1081.08 lb. 
Total downward pressure on & = 471.90 lb. 

A study of these figures shows the necessity of well-made flasks 
and bottom boards, for these must resist a greater pressure even 
than that required to keep the cope from lifting. They also 
show clearly why the lower parts of the casting resist the pres- 
sure of the gases more and require firmer ramming then the upper 
portions. 

Variation of Pressure Head. A difference in the way a pattern 
is molded may make a great difference in the weight required on 
the cope. Compare A and B, Fig. 30. Supposing this pattern 
is cylindrical in shape and with the dimensions as indicated, we would 
have the following basis: 



30 



FOUNDRY WORK 



Then 



Area of circle a = 113.10 sq. in. 

Area of circle b = 78.54 sq. in. 

Area of ring c'c^ (6 snbtracted from a) = 34.56 sq. in. 



Total lift on cope A is 8X.26X113.10 =235.24 lb. 

The lift on cope B is 8 X. 26X34.56= 71.88 
+ (8+5) X .26X78.54 = 265.46 
Total lift on B ■ = 337.34 lb. 



- /2- 



_^a_ 



-lO' 



CO 



lO 



Fig. 30. Diagram Saowing Difference in Pressure on Cope Due to Placing of Pattern 

yarkdion of Pressure Distribution. Fig. 31 is an example 
of a core 5 inches square surrounded by 1 inch of metal, with a 

runner 6 inches high. AYe have 
here : 

Pressure per square inch on a is 

7 X. 26 = 1.82 lb. 
Pressure per square inch on b is 
12 X. 26 = 3.12 lb. 
The difference in these pressures 
is 1.30 pounds per square inch. 
Then for every foot of length in 
the core we must balance a lifting 
pressure on the bottom of the core 
of5Xl2x3.12 = 187.2 pounds, until 
the metal covers surface a, when 
it will exert a counteracting down- 
ward pressure, and the strain on the chaplets will be only 
5X12X1.30 = 78 pounds. 



u 


< 


, II 

5 




— 








— 1 




'■J 














' / 








5" Core 








r '3\L 








t 





Fig. 31. Diagram Showing Difference in 
Pressxire on Top and Bottom 
of a Cube 



FOUNDRY WORK 31 

Common Defects in Castings. Some of the ordiiiary defects 
which the beginner will find on his castmgs are as follows: 

Short Pourings. The amount of metal in the ladle is misjudged 
with the result that the mold is not completely filled. 

BloicJioIes. These come from gases becoming pocketed in 
the metal instead of passing off through the sand. This is due 
to hard ramming, wet sand, etc. 

Cold-Shuts. These form when tAvo streams of metal chill so 
much before they meet, that their surfaces will not fuse when forced 
against each other, as illustrated in 
Fig. .32. 

Scuid Holes, These come from the ^. ^^ ^ ,j -.^_ 

Fig. 32. Cold-:^hut3 

washmg of loose sand or excess of facing 

into the mold cavity when pouring. They are usually bedded in 

the cope side of the casting. 

Scabs. Scabs show like small warts or projections on the 
surface of the casting. They result from small patches of the 
mold face washmg off. They may be caused from too much 
slicking, which draws the moisture to the surface of the mold, 
making the skin flake tmder the drying effect of the incoming 
metal. 

Swells. Swells are bulged places on a castmg and are due 
to soft ramming which leaves the walls of the mold too soft to 
withstand the pressure of the liquid metal. 

Shrinkage Cracks. These are due to unequal cooling in the 
castmg. They are sometimes caused by the mold bemg so firm 
that it resists the natural shrinkage of the iron, causing the metal 
to pull apart when only partially cold. 

Warping. This occurs when these strams cause the casting 
to bend or twist, but are not sufficient to actually crack the metal. 

TYPICAL MOLDING PROBLEMS 

General Precautions. When startmg to ram a flask, see that 
the sands to be used are well cut tlirough and properly tempered. 
Select a fiask large enough to hold the pattern and have at least 
2 inches clear of the flask all around for bench work, and 4 to S inches 
on floor molds, depending upon the weight of the work to be cast. 
See that the flask is strong enough to carry the sand without racking 



32 FOUNDRY WORK 

and that the pins fit. Have the necessary tools at hand, such as 
sieve, rammer, sHcks, etc. 

Jointing. Examine the pattern to be molded to see how it 
is drafted and note especially how the parting line runs. That 
part of the mold forming the surface between the parts of the flask 
is called the joint , and where it touches the pattern this joint must 
be made to correspond with the parting line. 

The joint of a mold may be a plane or flat surface, or it may 
be an irregular one. When the joint is a flat surface it is formed 
entirely by the mold board except with work bedded in the floor; 
there it is struck off level with a straightedge. When it is irregular 
the drag joint must be coyed out for every mold needed, that is, 
shaped freehand by the molder before making up the cope; or, by 
another method, the shape of the cope 
^ — joint is built up first in a match frame with 

the cope part of the pattern bedded into it, 
and upon this form the drag may be packed 
repeatedly, receiving each time the desired 
joint surface without further work on the 
T.. oo T^ , molder's part. 

Fig. 33. Faceplate ^ 

Our first problems in molding illustrate 
these three methods of making the joint. It is aimed to give the 
directions for making up molds in as concise a form as possible. 
The student should refer frequently to the preceding sections and 
familiarize himself with the reasons underlying each operation. 

Flat Joint. In the small faceplate shown in Fig. 33, all of 
the parting line aaa will touch the mold board, so the joint will be 
flat. The draft is all in one direction from the cope side c, there- 
fore all of the pattern will be in the drag. Use a snap flask for 
this piece. 

Molding Drag. Place a smooth mold board upon the bench 
or brackets. Place the drag with sockets down upon this. Set 
the pattern a little to one side of the center to allow for the runner. 
Sift sand over this about IJ inches deep. Tuck the sand firmly 
around the pattern and the edges of the flask as indicated by the 
arrows in Fig. 34, using the fingers of both hands and being careful 
not to shift the sand away from the pattern at one point when tucking 
at another. 




FOUNDRY WORK 



33 



MZ/'r/? Fingers 




Fig. 34. Molding Sand with Fingers 



Fill the drag level full with well-cut sand. With the peen end 
of the rammer slanted in the direction of the blows, ram first around 
the sides of the flask to ensure the sand hanging in well, as at 1 and 
2 in Fig. 35. Next carefully direct the rammer around the pattern, 
as at 5, 4* and 5, Do not strike closer than 1 inch to the pattern 
with the end of the rammer. 

Shifting the rammer to a vertical position, ram back and forth 
across the flask in both directions, being especially careful not to 
strike the pattern nor to ram too 
hard immediately over it. The 
student must judge by feeling when 
this course is properly rammed. 
Now fill the drag heaping full of 
sand. Use the butt end of the 
rammer around the edges of the 
flask first, then w^ork in toward the middle untU ,the sand is packed 
smooth over the top. With a straightedge strike off the surplus 
sand to a level with the bottom of flask. Take a handful of sand 
and throw an even layer about \ inch deep over the bottom of the 
mold. On this loose sand press the bottom board, rubbing it slightly 
back and forth to make it set w ell. With a hand at each end, grip 
the board firmly to the drag and roll it over. Remove the mold 
board and slick over the joint surface with the trowel. Dust part- 
ing sand over this joint (burnt core 
sand is good on this work), but 
blow it carefully off of the exposed 
part of the pattern. 

Set the wooden runner or gate 
plug about 2 inches from the pat- 
tern, as shown in Fig. 23, page 24. 
In snap work the runner should come as near the middle of the 
mold as possible, to lessen the danger of breaking the sides, 
and to allow the weight to be placed squarely on top of 
the mold. 

Molding Cope, Set the cope on the drag and see that the hinges 
come at the same corner. 

Sift on a layer of sand about 1§ inches deep. Tuck firmly 
with the fingers about the lower end of the runner and around 




Fig. 35. Molding Sand with Rammer 



34 



FOUNDRY WORK 




the edges of the flask. Fill the cope and proceed with the ramming 

the same as for the drag. 

Strike off the surplus sand, swinging the striking stick around 

the runner so as to leave a fair flat surface of sand. Partially shape 

a pouring basin as illustrated 
in Fig. 23, with a gate cutter, 
before removing the runner. 
Draw the runner and finish 
the basin with a gate cutter 
and gently smooth it up with 
the fingers. Carefully moisten 
the edges with a swab and 
blow it out clean with the 

Fig. 36. Use of Iron Band ■, i i n 

hand bellows. 
Lift the cope and repair any imperfections on the mold surface 
with the trowel or slicks. See that the sand is firm around the lower 
end of the runner. Blow through the runner and all over the joint 
to remove all loose parting sand. Slick over the sand which forms 
the top surface of the gate, between the runner and the mold. 

Having finished the cope, moisten the sand about the edges 
of the pattern with a swab. Drive a draw spike into the center 
of the pattern and with a mallet or light iron rod, rap the draw 

spike .slightly front and back 
and crosswise. Continuing a 
gentle tapping of the spike, 
pull the pattern from the 
sand. If any slight break 
occurs, repair it w^ith bench 
lifter or other convenient 
slick. Cut the gate and 
smooth it down gently with 
the finger; blow the mold out 
clean with the bellows. No 
facing is needed if the castings 
are to be pickled. The mold should now be closed and the snap 
flask removed. 

Strengthening against Pressure. There are two methods used 
to strengthen these molds against the casting pressure. One is 




Fig. 37. Weight in Position 



FOUNDRY WORK 



35 



to use an iron band which will just slip inside of the flask before 
the mold is packed, as in Fig. 36. The other is to slide a wooden 
slip case over the mold after the snap flask is removed, as in Fig. 37. 
In either case the weight, shown in position in Fig. 37, should not 
be placed on the mold until pouring time, lest by its continued 
pressure it might crush the sand. 

Coping Out. The second type of joint surface mentioned above 
is illustrated by the method of molding the tailstock clamp shown 
in Fig. 38. This is a solid pat- 
tern and rests firmly upon the 
mold board on the edges aa, 
but the parting line hhh runs 
below these edges. The bulk 
of the pattern drafts down from 
this line and so will be molded 
in the drag, while all above 

To mold the piece, set the pattern on the mold board, planning 
to gate into one end. Ram the drag, and roll it over, as described 
in the last example. With the blade of the trowel turned up edge- 
wise, scrape away the sand to the depth of the parting line, bringing 
the bevel up to the main level of the joint, about 2 J inches from the 
pattern, as shown at Fig. 39, and slick this surface smooth with the 




Fig. 38. Tailstock Joint 



it will be shaped in the cope. 




Fig. 39. Coped-Out Mold 



finishing trowel or leaf and spoon. This process is called coding 
out. Dust parting sand on the joint thus made. Be careful not to 
get too much at the bottom of the coping next the pattern. Pack 
the cope, then lift it, and finish the mold as directed. 



36 



FOUNDRY WORK 



Shape of Draft. In coping out, the molder practically shapes 
the draft on the sand of the drag. Aim to have the lower edge 
of the coping parallel with the main joint for a short distance, and 

then spring gradually up to it at 
about the angle shown in the sec- 
tion at c, Fig. 40, as this is the 
strongest shape for the sand. If 
made with an abrupt angle as in d, 
the cope sand will tend to wedge 
into the cut with the danger of a 
drop or break when the cope is 
lifted. 

In many cases, more especially in floor work, an abrupt coping 
angle may be avoided as follows : Set wooden strips, whose thickness 
is equal to the depth of the desired coping, under the edges of the drag 
when ramming up the pattern. (Use, for example, the hand wheel 



/ 


J 




"1 


••■.>T.-.^J 






; m 


k -.:■:'■ A 


m 




y\/y . >' 


T ' ': 


■ \.\ . 





Fig. 40. Angle of Joint 




Fig. 41. Molding a Hand Wheel 



shown in Pattern Making, Fig. 114.) When the drag is rolled over, 
the sand will be level with the top of strips and pattern at aa, Fig. 41. 
Remove the strips and strike surplus sand off level with edges of 
drag bb, and slick off the joint. Proceed with the cope in the usual 

manner. In gating this pattern, and 
wheels generally, place a small runner 
directly on the hub. 

Sand Match. The solid bush- 
ing. Fig. 42, serves to illustrate the 
use of a sand match. For exercise 
work, use only one pattern. 
In practice, however, several small patterns are bedded into 
the same match. It is clear that in this pattern the parting line 
runs along the center of the cylinder, and to make a safe lift for the 




Fig. 42. Solid Bushing 



FOUNDRY WORK 



37 



cope it should follow around the circumference of the ends ahcy 
as shown by the heavy lines. 

The frame for the match is shallow, and of the same size as the 
snap flask with which it is used. It is provided with sockets to engage 
the pins of the flask. The bottom board is fastened on with screws. 

Fill the match with sifted sand rammed hard. Strike off a 
flat joint and bed in the pattern. Cope out the ends to the lower 
edge of the pattern, as shown in Fig. 43, flaring it well in order to 
make a good lift. Slick the whole surface over smooth. Rap and 
lift the pattern to test the correctness of the work. 

Replace the pattern. Dust on parting sand and ram the drag, 
tucking carefully in the pocket at each end. Roll the two over. 
Lift off the match, and set it to one side. The pattern remains 




Fig. 43. Use of Sand Match 



in the drag. Dust on parting sand. Set the runner and ram 
the cope as described. When the mold is opened and the pattern 
is drawn, it should be set back immediately into the match, ready 
for use again. 

Usage. On account of economy of construction in the pattern 
.shop, irregularly shaped work is often made in one piece. The 
molder must then decide whether it is cheaper to cope out each 
joint or to make up a sand match. Where the number of castings 
required is small, or where the pattern is large, it is better to cope 
out. But where a number of castings is required it is cheaper 
to make up a sand match. For methods of making quantities of 
castings and the use of a more permanent match, see the section on 
Duplicating Castings. 



38 



FOUNDRY WORK 



In the foregoing the main use of the match was to save time. 
It frequently happens that a pattern is so irregular in shape that 
it will not lie flat on the board in any position. In this case, a match 
is absolutely necessary before the drag can be packed. For large 
patterns, the cope box of the flask is used to bed the pattern into instead 
of a separate frame. After the drag has been packed upon it and 
rolled . over, this first cope is dumped, and the box repacked 








*t*-^fe* « 






(gsi^^^Sai^SiS 







J-^Gttern on mo/c/ I)oarc/ 



Fig. 44, Split- and Loose-Piece Patterns 

with the necessary gaggers, vents, runners, etc., required for casting. 
The first cope is then termed, not a match, but Si false cope. 

For very light wooden patterns which may or may not have 
irregular parting lines, the pattern-maker builds up wooden forms 
to support the thin wood while the drag is being packed and to 
give the proper joint surface to the sand. This board serves exactl}^ 
the same purpose as the sand match and false cope, but it is termed 
a follow board. See article on Pattern-Making. 

Split=Pattern Molds. So far the patterns used have been made 
in one piece, but a flat joint is the most economical for the molder, 



FOUNDRY WORK 



39 



when many castings are required. Generally such pieces as bushings, 
pipe connections, and symmetrical machine parts are made in halves; 
one piece of the pattern remaining in each part of the flask when 
the mold is separated. There are many cases, too, where, to make 
a flat joint for the mold, the pattern maker can separate one or 
more projections so as to have the main part of the pattern in the 
drag and to let these loose parts lift off in the cope. 

The small punch frame and the gas-engine piston, shown in 
Fig. 44, are examples of these two classes of patterns. At A, the 
sections through the patterns show the methods of matching them 
together. B shows the drag parts of the patterns in position for 
molding. At C, is the section 
through the mold and the plan of 
the drag showing how the gates are 
connected. Attention is directed to 
the use of the horn sprue — the sprue 
pattern is shown at a — by which the 
metal enters the mold at the bottom. 
If the gate were cut at the joint sur- 
face, there would be danger of cutting 
the sand on top of the green-sand 
core b as the metal flowed in upon it. 

Loose-Piece Mold. It often hap- 
pens that bosses or projections are 
required on a casting at right angles 
to the main draft lines of the pattern 
and below . the joint surface. Examples of such cases are shown 
in Pattern-Making. In molding such work, care must be taken 
that the overhanging portion of sand shall be strong enough to 
support itself. Where the projection is deep, the mold should be 
strengthened by nails or rods, as shown in Fig. 45. These should be 
wet with clay wash and set into the sand, when the mold is rammed. 

Use of Green-Sand Core. Some work has projections on it 
which lie above or below the parting line in such a way that it cannot 
be molded by either of the foregoing methods. Examining the 
patterns for some of this work, we find two entire parting lines with 
the pattern made to separate between the two. Such patterns 
require between the drag and cope an intermediate body of sand, 




Fig. 45. 



Strengthening Mold with 
Iron Rod 



40 



FOUNDRY WORK 



from the top and bottom -of which the two parts may be drawn. 
In small work, as illustrated by the groove pulley, this inter- 
mediate form is held in place by the sand joint of the cope and 
drag, and is termed a green-sand core. The method of molding 




Fig. 46. Section of Mold 

such a piece is given in Pattern-Making, Part I. To provide for 
pouring the casting, a runner should be placed on the hub of the 
first part packed C, Fig. 46, which shows a section of the mold before 
either part of the pattern has been removed. When the flask is 
rolled over to remove the final part C of the pattern, the runner is 
on top ready for pouring. 




Fig. 47. Part Section of Mold Showing 
Use of Core-Iiifting Ring 




Fig. 48. Pattern Shown in Fig. 47 
with ISIold Complete 



Core-Lifting Ring. Another method used does away with 
rolling the entire flask. A core-lifting ring is first cast slightly larger 
in diameter than the flange of the sheave, and having such a section 
as shown in a, Fig. 47. The ring is set in position in the middle 
of the inverted drag, the pattern is held central inside of the ring 
by the recess in the mold board. Pack the drag, roll over, and 
remove the mold board. Tuck the green core all around and 



FOUNDRY WORK 



41 




Fig. 49. Casting for Ten-Incb 
Nozzle 



slick off the top joint of the core. Pack the cope in the usual way, 
lift it off, and draw the cope pattern. Now, by means of lugs cast 
on this lifting ring, the green core may 
be lifted off of the drag pattern, allowing 
it to be removed. Replace the ring and 
close the cope; and the mold is com- 
plete, as shown in section. Fig. 48. 

Three-Part Mold. In larger work, 
where the parting planes are. farther 
apart, this intermediate body of sand 
is carried in a cheek part of the flask, 
and we speak of it as three-part work. 

Fig. 49 shows a casting for a 10- 
inch nozzle, the mold for which illus- 
trates this class of work. Here the pattern is separated just 
above the fillet of the curved flange. Fig. 50 gives a view of the 
mold, showing the way 
the joint is formed. 

This casting should 
be made on the floor. 
Select a square flask, 4 
inches on a side larger 
than the diameter of 
the flanges. The cheek 
should be as high as that 
part of the pattern which 
is molded in it. There 
should be two projecting 
bars on opposite sides 
of the cheek to support 
the sand, and crossbars 
in both drag and cope. 
These should be well wet with clay wash before using the boxes. 
Set the pattern centrally inside the cheek, and place a runner 
stick just the height of the pattern in one corner of this box. On 
account of the depth of the cheek, the sand must be rammed in 
two courses. Sift enough facing sand into the box to cover the 
joint and 5 inches up around the pattern to a depth of about li 




Fig. 50. Casting of a Nozzle 



42 



FOUNDRY WORK 



inches, tucking about the pattern with the fingers. Fill in about 5 
inches of loose sand and before ramming tuck around the ends of 
the side bars, compressing the sand between the finger tips, having 
a hand on each side of the bar, as illustrated in Fig. 51. Now use 
the peen end of the floor rammer in the same general way as the 
hand rammer is used in bench molding. Guide the rammer around 
the sides of the flask and bars first, then direct it toward the bottom 
edges of the pattern. As the sand gradually feels properly packed 
at this level, direct the blows higher and higher up. Proceed in this 
way to within about 1 inch of the drag joint. Make this joint by 
ramming in sifted facing sand, being careful to tuck it firmly under- 
neath the flange. Cope this joint to the 
shape of the curved flange. 

Dust on parting sand. Place the 
drag in position and ram it up in the 
usual way, only using facing sand next 
the joint and pattern. Place six long 
gaggers to strengthen the sand which 
forms the inside of the casting. Clamp 
the drag to the cheek and roll them over. 
Test, repair, and dust parting sand on 
the joint. Try the cope. The bars 
should clear the pattern and joint by 
about 1 inch. Set the cope runner about 2 inches to one side of the 
cheek runner and set the riser in the corner opposite. Sift on facing 
sand and tuck well with the fingers under the crossbars. Shovel 
in well-cut sand and finish packing the cope. Form a pouring 
basin, and vent well. Lift the cope. Draw the pattern from the 
cheek. Join the runners on the cope joint and connect the mold 
with the riser. Lift the cheek and repair it. Draw the drag pat- 
tern. All of the mold surfaces should have black lead facing brushed 
over them with a camel's hair brush, and this facing slicked over. 
Cut a gate on the drag joint. Close the cheek on the drag. 
Close the cope on the cheek, and the mold is ready for clamping* 
Floor Bedding. Owing to the development of the electric crane, 
there is much large w^ork now rammed in iron flasks and rolled over, 
which was formerly always bedded in the floor. This method is still 
much used in jobbing shops to avoid making a complete large flask. 




Fig. 51. Tucking Sand under Bars 



FOUNDRY WORK 



43 



The mold shown in Fig. 52 illustrates the principal operations 
involved. The casting is a flask section for a special steel-ingot mold, 
and in design is simply a heavy plate braced on one side by flanges 
and ribs of equal thickness. For convenience in ramming between 




Iron Rods 



Fig. 52. Casting of Flask Section 



the flanges, portions of the top plate of the pattern are left loose, 
as seen in Fig. 53. 

Pit. Dig the pit for the mold 10 inches larger on each side 
than the pattern, and about 6 inches deeper. Having screened 
some hard cinders through a No. 2 riddle, cover the bottom of the 



44 



FOUNDRY WORK 




Fig. 53. Bedded-In Work 



pit with them to a depth of 3 inches. Ram these over with a butt 

rammer, and at one end set a piece of large gas pipe. Put a piece 

of w^aste on the top of this to prevent its getting choked with sand. 

Ram a 3-inch course of sand. over the cinder bed and strike it off 

_, _. . level at the depth of the 

These F*/eces Loose p n 

/ \ V pattern from the floor 

line. Sift facing sand 
over this where the pat- 
tern will rest; set the pat- 
tern, and with a sledge, 
seat it until it rests level. 
Remove the pattern and 
with the fingers test the firmness of packing all over the mold. 
Vent these faces through to the cinder bed, and cover the vent 
holes with a |-inch course of facing sand. Now replace the pat- 
tern, and bed it home by a few more blows of the sledge. The 
top of the pattern should now be level and flush with the floor 
line. Seat the runner sticks, and, to prevent the sand on the bottom 
of the runners from cutting, drive 10-penny nails about f inch apart 
into this surface until the heads are flush. Ram the outside of the 
mold the same as if in a flask, and strike a joint on top. Ram 

green sand between the inside 
webs of the pattern, and 
strike off at the proper 
height with a short stick a, 
Fig. 54. Drive long rods 3 
inches apart into these piers 
to pass through to solid sand 
below the cinder bed. 

Vent all around the pat- 
tern, outside and inside, 
through to the cinder bed. 
On top of the inside piers 
cover these vent holes with facing sand, ram, and slick to finish; 
then cover with the loose pieces of the pattern. 

Cope. Try the cope and stake it in place; set the risers and vent 
the plugs. Ram the cope, slicking off level for about 2 mches around 
the top of the risers, to receive a small iron cover. 



'Runner Stick 
rFloo r Line 




/Vaifs-^^ 



: i'c: 



Fig. 54. Section Showing Method of Molding 



FOUNDRY WORK 



45 



Lift the cope, repair, and face with graphite. Draw the pattern 
with the crane and finish the mold. Connect the outer vent holes 
by a channel with the vent plug. From the end of each core 
print hbbhf Fig. 53, vent through to the cinder bed, and set the cores. 
Close the cope. Set the runner box against the side of the cope 
and build a pouring basin with its bottom level with the top of 
the risers. 

In weighting, great care must be exercised not to strain the cope. 
Place blocking upon the top ends of cope. Across these lay iron 
beams which will be stiff enough to support the load, and pile weights 




Fig. 55. Leveling a Bed for Open Sand Work 



on these, as shown in Fig. 52. Now wedge under the beams to the 
crossbars of the cope at necessary points. 

Open Mold. There is a large class of foundry rigging, such as 
loam plates, crossbars, and sides to iron flasks, which may be cast 
in open molds. As there is no head of metal, the beds must be 
rammed only hard enough to support the actual weight of the metal, 
or it will boil. To insure uniform thickness in the casting, the bed 
must be absolutely level. 

Drive four stakes aaaa, as shown in Fig. 55, and rest the guide 
boards ^^ on the top of these. By using a spirit level bb, make 



46 



FOUNDRY WORK 



these level, and bring them to the same height by testing with the 
straightedge B, 

The space between the guide boards A A should be filled with 
well-cut sand even with their tops dd. Sift sand over the entire 
surface. Strike this sand off f inch higher than the guides, by 
placing a gagger under each end of the straightedge, as it is drawn 
over them. Tamp this extra sand to a level with the guides by 
rapping it down with the edge of the cross-straightedge, and the bed 
will be as shown in Fig. 56. We can now proceed to build up 



Pouring 
Basin 




SegmenT 
'lock ' 



^Overf/ow^^ 



Fig. 56. Open Sand Mold 

to a segment of pattern, or with a sledge drive a pattern into this 
surface. 

The pouring basin should drain itself at the level of the top of 
mold, and an overflow may be cut on one edge to drain the casting 
to any desired thickness. 

CORE WORK 

Reference has been made in the first part of this article, under 
Divisions of Iron INIolding, to the general difference between core 
work and green-sand work. This, and the section on Sands, the 
reader should review carefully. 

Dry=Sand Cores 

Materials. &and. Here, as in green-sand molding, the prin- 
cipal material used is a refractory sand. In molding sand, however. 



FOUNDRY WORK 47 

the alumina or clay forms a natural bond in the sand. To meet 
the necessary requirements of cores we must use a naturally free 
sand as a base, and give it bond by adding some form of organic 
matter as a binder, then bake the core. 

Binders. The most common binders are the following four 
materials: Ordinary wheat flour is an almost universal material 
for use as a core binder. Every one is f amihar with its action when 
moistened and baked. The hard vegetable gum rosin — a by- 
product of the manufacture of turpentine — for use as a core binder, 
should be reduced to a powder. It melts under the heat of the oven, 
flows between the grains of sand, and upon cooling binds them 
firmly together. Linseed oil, made from flaxseed, acts in a way 
similar to rosin; a small proportion of oil together with some flour 
makes a very strong core. Glue, which is obtained from animal 
hoofs and from fish stock, is also used to some extent as a core 
binder. It should be dissolved in water before mixing with 
the sand. 

Tempering. A weak molasses ivater is used for tempering the 
sand for small cores; and on the larger work the same purpose is 
served by clay wash. There are many patent combinations of the 
above or similar materials put on the market as core compounds. 
There are two classes of these: dry compounds, and liquid com- 
pounds. The advantages claimed for them is that they are more 
economical — (1) because a smaller proportion of the compounds 
is sufficient to obtain the desired results; and (2) because a large 
proportion of the sand may be used over and over again. 

Reinforcement. Among other necessary core-room supplies are : 
annealed iron wire No. 6 to No. 16, and round bar iron in sizes |-inch, 
f -inch, |-inch, f -inch, and f -inch, which are cut to length as needed, 
and are bedded in the core sand to strengthen the core, as will 
be demonstrated later. 

Venting. A supply of clean cinders must be available also for 
venting larger cores. Small wax tapers make good vents for crooked 
cores. There is also a patented wax vent for sale on the market. 

Facing. As before stated, charcoal with some graphite is the 
principal facing material used on cores. It is always applied in liquid 
form by dipping the core or by using a flat brush having extra 
long bristles. 



48 



FOUNDRY WORK 




Fig. 57. Spraying Can 



Equipment. General Tools. The general tools of the core room 
are similar to those already mentioned. A piece of iron rod very 
often replaces the regular rammer on account of the small size 
of the opening into which sand must be packed. 

The trowel is the most common slick, because most of the sur- 
faces which require slicking are flat ones formed by striking off 
after packing the box. Except in the largest work, the entire face 

of the core is not slicked over, 
so a variety small slicks is 
not needed. 

A spraying can, shown in 
Fig. 57, is used for spraying 
molasses water over small cores. 
Fill the can two-thirds full and 
blow into the mouthpiece. 

Small cores are made up 
on a flat bench, the sand being in a small pile at the back. 
Larger boxes are rammed up on horses or on the floor, as is most 
convenient. 

Baking, After being made up, cores are baked on core plates. 
The smaller plates are cast perfectly flat. Plates over 18 inches 
long are strengthened by ribs east about 1 inch from the edge, 
as shown in Fig. 58; this keeps the plate from warping, and admits 
of its being picked up readily from a flat bench top or shelf. 

Ovens are built with reference to the size of the cores to be baked. 
A good type of small oven is illustrated in Fig. 59. It can be run 

very economically with either 
coal or coke, and bakes cores 
up to 2 inches in diameter 
within half an hour. Each 
shelf is fastened to its own 
door, and, when open for receiving or removing cores, a door at 
the back of the shelf closes the opening. This prevents a waste 
of heat. 

Fig. 60 shows the section through an oven suitable for the largest 
work, including dry-sand and loam molds. The fire box A is situated 
in one corner at the back; its whole top opens into the oven. At 
the floor level diagonally opposite is the flue B for conducting the 




Fig. 58. Core Plate 



FOUNDRY WORK 




49 



Fig. 59. Small Core Oven 




FU.60. Core Oven f„. Large Work 



50 



FOUNDRY WORK 



waste heat to the stack C. The entire front of the oven may be 
opened by raising the sheet-steel door. Two tracks side by side 




r^ 



""""l""''!'!l'''li'iiillr»f 



™«!ll"''l'llllliHI] 



(lum 



S 






Fig. 61. Cast-iron Car 

accommodate cars upon which heavy work is run into the oven. 

Fig. 61 shows a good form of cast-iron car. The w^heels aredesigned 
on the roller principle to make it easier to start the 
car when heavily loaded. 

For medium work smaller ovens of this type 
are used. Racks similar to the one shown in 
Fig. 62 may be bolted on the sides, arranged 
to hold the ends of the core plates; and the car 
may carry a line of double racks to increase the 
capacity of the oven. 

Conditions of Use. As mentioned before, 
cores form those parts of a mold which are to be 
nearly or entirely surrounded by metal; in other 
words, such parts as would be in danger of breaking 
or require too much work to be constructed in 
green sand. The object, then, in making cores is 
to insure a better casting and to reduce costs. 

Cores are held in position by means of core 
prints (see Pattern-Making). The main weight 
of the core is supported by these prints and 
through them all vent must be taken off and all 
sand removed in cleaning. Therefore, cores must 
be stronger than green sand, because, whether large 
or small, they must stand handling while being 
set and must not cut or break during pouring. 
Fig. 62. Rack They require greater porosity than green sand 

because their vent area is limited and their composition contains 

more gas forming material. Furthermore, cores must lose all their 




FOUNDRY WORK 51 

bond by the time the casting is cold, so that the sand may be easily 
removed no matter how small the available opening. 

These conditions are obtained by using a coarse free sand and 
a binder. To give additional strength when necessary, iron wire 
or rods, or cast-iron core arbors are bedded in the core. These 
serve the same purpose in a core that the flask does in green- 
sand work. 

Binder. The action of the binder enables the sand to retain 
its shape when the box is removed, and renders the core hard and 
strong when baked. In the mold the intense heat of the metal 
gradually burns out the organic matter or binder, leaving the 
core without bond. In this condition, the sand may readily be 
removed. 

Too much binder tends to make the core sag out of shape before 
baking, and blow when metal strikes it; that is, give off more gas 
than the vents can carry away. With too little binder the sand 
does not bake hard, and cuts when the mold is poured. 

The effectiveness of all binders, especially flour, depends upon 
their thorough mixing with the sand. The especial value of rosin 
and oil lies in the fact that by melting under the oven heat they 
form a more perfect bond with the sand. 

Many intricate cores are now made with an oil mixture, without 
using rods or wires, which formerly were considered absolutely 
necessary for strength. Such cores must be well supported when 
green, must be thoroughly baked, and handled with much care until 
they are cold. 

Core-Sand Mixture. No universal mixture for core sand can 
be given, as sands vary so much in different localities. The mixtures, 
as shown on the following page, illustrate approximate proportions. 

In preparing core sand, the different ingredients should be 
measured out, thoroughly mixed, and sifted while dry. Temper the 
mixture a little damper than molding sand. Too much moisture 
makes the sand stick to the box. Not enough makes it hard to 
work and gives a crumbly surface if dried. 

Facing. Blacking for light work should include one cup of 
molasses to a pail of water, into which is worked powdered charcoal 
until an even black coating is deposited upon the finger when dipped 
into the blacking and out again. 



52 



FOUNDRY WORK 
Core Mixtures 



Materials 


Small Cores 
(parts) 


Large Cores 
(parts) 


Intricate 

Smaller Cores 

(parts) 


Beach sand 
Fire sand 
Molding sand 
Sharp fire sand 
Strong loamy sand 
Flour 
Rosin 
OU 


10 

'1 


8 
2 


15 
15 

1 

2 


15 
5 

2 
1 


Tempering means Molasses water 


Clay wash 


Molasses water 



For heavy blacking there should be used about 2 parts charcoal 
and 1 graphite, mixed into thick clay wash. 

Miscellaneous. In finishing small cores, they should be sprayed 
with weak molasses water w^hile green, then well baked and removed 
from the oven. When cool enough to handle, they are dipped into 
the blacking; then put back in the oven until this facing has dried. 
For large cores the blacking is applied with a brush before baking. 

All cores should be baked as soon as made, for air-drying causes 
the surface to crumble. 

Cores must not be set in a mold while they are hot, or the mold 
will sweat, that is, beads of moisture will form on the inside faces. 
This would make the mold blow when poured. 

A core should be rammed evenly and somewhat harder than a 
mold. Too hard ramming will make the sand stick in the box, 
besides giving trouble in casting. Too light ramming makes a 
weak core. 

From the very nature of cores, the matter of venting them is 
very important and often calls for much ingenuity on the part of 
the core maker. 

For simple straight work a good sized vent wire is run through 
before the box is removed. Half cores have their vents cut in each 
half before pasting together. Cinders are rammed in the center 
of large cores connecting through the prints, with the mold vents. 
For crooked cores, wax ventc are rammed in the center — the wax 
melts away into the sand when the cores are baked, leaving smooth 
even holes. This is illustrated in one of the following examples. 



FOUNDRY WORK 



53 



Methods of Making. The examples here given serve to illus- 
trate the principal methods used in making cores. 

Small Cylindrical Core. The simplest form of core is one which 
can be rammed up and baked as made by simply removing the box. 
Short bolt-hole cores, etc., are made in this way, as shown in Fig. 63. 



^ 


x< 






n 


{ 1] 


1 


X 


^ 


HI 


'; 


jiji 




^ I 


L ';., 


life 


^^^^^^ 








Fig. 63. Short Bolt-Hole Cores 

Set the box on a flat bench top. Hold the two halves together 
by the clamp A. Ram the hole full of core sand by the use of a 
small rod. Slick off the top; run a good sized vent wire through 
the middle of the core. Remove the clamp. Set the box onto 
the core plate, rap the sides, and carefully draw them back from 
the core. 

Symmetrical ShaiJes. Larger cylindrical cores, up to about 
IJ inches diameter, ate rammed in a complete box also, only they 
are rolled out on their sides, as shown in Fig. 64. This, however, 
tends to make a flat place on the side, from the weight of the sand 
supported on this narrow surface. 

For this reason cylindrical cores of large diameter, and many 
symmetrical shapes, are 
made in half boxes. See 
Pattern-Making, Figs. 
110, 208, 213, and 219. 
Such boxes are rammed 
from the open side. 
Wires are bedded when 
necessary about in the middle of the half core. The fingers and 
the handle of a trowel are often used to ram the sand, and with 
the blade of the trowel the sand is struck off and slicked to the level 
of the top of the box. 

When baked, two half cores are held with their flat sides together, 
and any slight unevenness in the joint removed by a gentle rubbing 




Fig. 64, Large Cylindrical Cores 



54 



FOUNDRY WORK 



motion. A vent channel is then scraped centrally on each half. 
Paste, made of flour and molasses water, is applied around the edges 
and the two halves pressed firmly together; care is taken to see 
that they register all around. The core should then be placed in 
the oven to dry out the paste. When pasting cores of 6-inch diam- 
eter and over, it is well to bind the halves at each end with a single 
wrap of small wire. 

Proper Seating, Wherever possible, core boxes should be made 
with their widest opening exposed for packing the core, and designed 
so that the core may rest, while being baked, on the flat surface 
formed by striking off at this opening. 

Core plates will sometimes become warped. When a core would 
be spoiled by resting it directly upon such a plate, the unevenness is 





Fig. 65. Bedding a Crooked Core 



overcome by sifting upon the plate a thin bed of molding sand and 
seating the core on this. 

Crooked Shapes, All cores cannot be made with a flat surface 
for baking, as illustrated by a port core, the box for which is shown 
in Pattern-Making, Fig. 251. This core must be rolled over on a 
bed of sand. Using an oil mixture, ram the core carefully, bedding 
into it several wax vent^. These should start near the end which 
will touch the main cylinder core and lead out of the end which 
will enter the chest core. To get this crooked core on a plate for 
baking, a wooden frame is roughly nailed together, which is large 
enough to slip over the core box when the loose pieces have been 
drawn off of the core, as shown in A, Fig. 65. 

The space on top of the core is now filled with molding sand, 
rammed just enough to support the weight of the core. The edges 
of the frame project above the highest points of the core and form 
guides for striking off this sand and seating a core plate, as at B, 



FOUNDRY WORK 



55 



Fig. 65. Box, frame, and plate are now firmly clamped and rolled 
over, and the frame and box removed, leaving the core well bedded 
on the plate ready for the oven, as at C. 

In manufacturing plants quantities of cores are often required 
which cannot be baked on a flat plate. To save the time and material 
necessary to roll each core onto a bed of sand, metal boxes are made, 
Pattern-Making, Figs. 233 and 234, and the core is baked in 
one part of the box. Only one casting is required of the larger 
portion of the box. The smaller part is duphcated for every core 
required for the day's 
mold.* 

Rod Reinforcing. 
Mention has been made 
of the use of wires for 
strengthening small 
cores. In making larger 
ones, there is a greater 
weight of sand to cause 
strain in handling the 
core, and proportionately 
greater casting strain. 
To resist these stresses 
a systematic network of 
rods is bedded in the core 
while being rammed, as 
shown in the sectional 
view. Fig. 66. Heavy 

bars aabh extend the length of the core to give the main stiffness. 
Smaller cross-rods rest on these at the bottom and top, and with 
the small vertical rods tie the whole core together. 

At even distances from each end lifting hooks c are placed. 
Cross-rods through the lower eyes of these hooks bring all the strain 
of the lift on the long heavy core rods. The holes in the top of the 
cores where the lifting hooks are exposed, are stopped off when the 
core is in the mold, by moistening the sides of the holes with oil 
and filling up with green sand. 

Cinders are packed in the middles of such cores. They aid 
in drying the core. They furnish good vent, and they allow the sand 




Fig. 66. Network of Rods in Cores 



56 



FOUNDRY WORK 




Fig. 67. Sections Showing Use of Cast 
Iron Core Arbor 



to give when the casting shrinks, thus reheving the strain on the 
metal itself. 

Use of Arbors. For the largest class of cores for green-sand 
work, cast-iron core arbors are used, of which a very satisfactory 

type is shown in Fig. 67. This 
consists of a series of light rings. A, 
carried on a cast-iron beam, B, The 
rings are of about |-inch metal cast 
in open sand and set about 8 inches 
on centers, and may be wedged to 
the beam. The beam has a hole at 
each end for lifting the core. 

This skeleton is made up and 
tried in the box before the work of ramming the core is begun. It 
is then removed and given a coat of thick clay wash. A layer of 
core sand is first lightly rammed over the inside of the box, and 
the core arbor seated into this. The full thickness of core-sand 
facing is then firmly rammed, and the entire center filled with well- 
packed cinders. Vents through the facing at both ends provide for 

the escape of gases from these 
cinders. 

Sweeping, Often, when but 
one or two large cores are wanted, 
the cost of making a box is saved 
by sweeping up the core. This 
is illustrated in the pipe core 
shown in Fig. 68. 

The pattern-maker gets out 
2 core boards and 1 sweep. The 
boards are made by simply nail- 
ing together 3 thicknesses of 
I -inch stuflP, with the grain of the 
middle piece crossing that of the 
others to prevent warping. The 
outer edges of the boards have the exact curve of the outside of 
the pipe pattern, and at the ends is tacked a half section of the 
core, shown at aa. One sweep does for both boards. The curve 
is cut the exact half section of the core. The edge b equals the 




Fig. 68. Pipe Core 



FOUNDRY WORK 



57 



thickness of metal in the casting, and the stop c acts as a guide 
along the outer edge of the board, 

In making up this core, a thin layer of core sand is spread on 
the board and the outline of the core swept. On this the rods with 
their lifting hooks are bedded, and the vent cinders are carefully 
laid along the middle. The whole general shape is then rammed 
up in core sand larger than required, and by using the sweep it is 
brought to exact size. The core is then slicked off, blackened, 
and baked while still on the board. When both halves are dried, 
they are pasted together, the same as with smaller work. To 





fimm^^>^m^>!^^^^^s^^m^m^. 



Fig. 69. Core Machine 



prevent breaking the lower half when turning it over to paste, it 
is rolled over on a pile of heap sand. 

Core Machines. For making stock cores, round or square, 
several styles of core machines have been put on the market within 
the last few years, of which the one illustrated in Fig. 69, is a good 
representative. This is arranged to be driven by hand or by power. 
The core sand is placed in the hopper, and by means of a horizontal 
worm at the bottom it is forced through a nozzle under just the 
right pressure to pack the core firmly. A clean-cut vent hole is 
left in the middle of each core. As the core is forced from the 
nozzle it is received on a corrugated sheet-steel plate, which is moved 



58 



FOUNDRY WORK 



along to the next groove when the core has run to the full length 
of the plate. 

The advantage of the machine is that with it an apprentice 
boy can produce a true, smooth, perfectly vented core, in very much 
less time than could possibly be done by hand-ramming. 

Setting Cores 

Cylindrical Cores. Plain Fitting, Among the followmg exam- 
ples showing typical ways of setting and securing cores in molds 
and of connecting vents, the bolt-hole core, shown at A, Fig. 70, 
illustrates the simplest form of core to set. Only a drag print is 
necessary; the flat top of the core should just touch the cope surface 
of the mold. The level may be tested by a straight stick or by 




Fig. 70. Bolt-Hole Core 



Fig. 71. Calipers 



sighting across the joint. If the core is too long, one end may be 
filed off a little, if too short, a little sand may be filled into the bot- 
tom of the print. For longer cores, especially hub cores, a taper 
print is placed on the cope side of the pattern, and the same taper 
is given to the end of the core; this guides it to the exact center 
when the mold is closed. Numerous examples are shown in Pattern- 
Making. The exact length of the core should be obtained from 
the pattern with a pair of calipers, as shown in Fig. 71. One 
point of the calipers should then be placed on the taper end of 
the core, and the print filled in, or the core shortened in case of 
variation from the right length. It is well to make a vent hole 
from the center of each print before setting the core. 

With pattern and core boxes properly made, little difficulty 
should be experienced in setting small horizontal cores for hollow 
bushings, pipe connections, etc. (See Pattern-Making, Figs. 110, 



FOUNDRY WORK 



59 



203, and 210.) The core must fit the print or a poor casting will 
result. The sand supporting the prints must be tucked firmly 
enough to withstand the lifting pressure on the core. A scratch 




vgs.rt.A. 




Fig. 72. Supported Body Core 

with the point of the trowel along the joint surface from the end 
of the print to the edge of the flask, will usually take care of 
the vent. 

For larger cores of this character crossbars made to fit snug 
against the core print are nailed in both drag and cope. See aaaa. 
Fig. 72. These hold the core absolutely firm. The spaces bb in 
the cope, are hot packed until the core is set, when it is a simple 





Fig. 73. Setting Core below Surface 

matter to ram these spaces and take off an air vent directly from 
the center of the core. 

Holes below Joint Level. There are two methods of coring 
holes below the level of the joint. One is shown clearly in Fig. 73. 



60 



FOUNDRY WORK 



Cg^sJ 



[Fig. 74. Gage for Setting Chaplets, 



A stock core is set in the bottom of the prints; a wooden template, 
shown at b and b\ is set over the core, and the print a is then 
packed with molding sand, or stopped off, as it is termed. 

The other method is shown at B and B\ Fig. 70. Here that part 
of the core which will shape the hole through the casting, is 

formed on the end of a core which 
exactly fills the print. A single oper- 
ation sets the core and stops off the 
print. For this reason this method 
is used w^here a large number of 
such holes are to be cored. 

Setting Chaplets. In setting 
chaplets, the height of the lower 
one may be tested with a rule, with a straightedge rested on the 
prints, or by a gage similar to that shown in Fig. 74. A small boss 
is usually formed by pressing the trowel handle into the mold where 
the chaplet is to go. 

The cope chaplet is not fastened until the mold is closed, then 
the stem can be properly wedged down under a oar clamped across 
the top of the mold. 

Projecting Cores. Balanced Type. In w^ork w^here a hole 
must project well into the casting, but [not all the way through it, 
a balanced core is often used. Such a case is illustrated by the 
rammer head. Fig. 75. ^^Tlen making this core, let the vent extend 
through the entire length, then stop up the vent at the small end 

with a bit of clay after the core 
is baked. 

It is not always practicable 

to enlarge the print as shown 

here, but when possible, it reduces 

the length of print necessary to 

balance the projecting end and 

ensures accurate depth to the 

hole. 

Heavy Form. Hea\y projecting cores must be supported by 

chaplets, as illustrated in Fig. 76. Vents may be taken off through 

a channel and air riser as explained in the section on Venting. Fig. 77 

shows the shape of the print on the pattern for this mold at a, the 




Fig. 75. Small Balanced Core 



FOUNDRY WORK 



61 



pockets formed by the core are shown at bb, and c indicates the 

position of the gate. 

Hanging Cores. A core is frequently used to avoid a deep 

lift for the cope. Suitable wire hangers, shown at a, Fig. 78, are 

bedded in the core when it is 
made. In setting the core, small 
annealed wire about No. 20 or 



l^&nt 




Fig. 7Q. Large Balanced Cor© 



Fig. 77. Shape of Print on Pattern for 
Projecting Core 



No. 24 gage is looped through the hangers, passed through small 
holes made in the cope, and fastened with a granny twist over an 
iron bar on top. This bar should bear on the sides of the cope and 
the core be brought up snug in its print by wedging under its ends. 
The rigging need only be strong enough to support the weight of the 
core, for the pressure of metal will force this core firmly into its 
print with little danger of Wire 

shifting it. For heavy cores, ^ "^ 

a lifting eye, as previously 
illustrated in Fig. 66, takes 
the place of the wire hanger, 
and the core is hung by means 
of a hooked rod with a nut on 
the end. As shown in Fig. 79, 
this rod passes through a long 
washer which bears on a pair 
of rails, or similar stiff rigging. 
Bottom=Anchored Cores. 
Where possible, the placing of 
cores in the bottom of molds should be avoided, for in this position, 
being much lighter than molten iron, they must be secured against 
a pressure tending to float or lift them. This pressure is propor- 
tionate to their depth below the pouring basin. But the metal 




Fig. 78. Section Showing Use of Wire Hangers 



62 



FOUNDRY WORK 



at the bottom of a mold is cleaner and more sound than that at 
the top. Therefore, planer beds, large faceplates, and pieces of 
this character are usually cast face downward, making it necessary 

to anchor the T-slot cores in the 
bottom of the mold. 

In some cases, such cores 
may be held down by driving 
nails so that their heads project 
somewhat over the ends of the 
core, as shown in Fig. 80. If 
this method is not strong enough, 
pointed anchors, with a foot on 
one end, are run through a hole 
in the core, and are carefully 
driven into the bottom board, as 
shown in Fig. 81. Where the 
work is bedded into the floor, a 
plank must be set to receive these 
anchors just below the cinder 
bed. As in the case of lifting eyes, the holes in the core, into 
which the foot on the anchor is driven, are smeared with oil and 
stopped off with green sand. 




Fig. 79. 



Section Showing Use of Lifting Eye 
for Heavy Cores 



Joint Line 




Fig. 80. Section Showing Use of Nails to 
Hold Cores in Place 



Fig. 81. 



Section Showing Use of Anchors 
to Hold Cores in Place 



Qreen=Sand Cores 

Expediency in Use. Many times the jobbing foundry may 

find it expedient, where patterns and core boxes are furnished by 

the customer, to make certain changes which will reduce the cost 

of production; for, unhappily, the patterns furnished sometimes 



FOUNDRY WORK 



63 



show a great desire on the part of the pattern-maker to produce 
the patterns cheaply, without making due allowance for difficulties 
encountered in the foundry. 




Fig. 82. Half Core with Box Built around It 



Typical Instance. The practice of substituting green-sand 
cores for dry sand has many possibilities. As an example, consider 
the case of a flange and spigot pipe 72 inches long and 6 inches 



tfov^el or Drag 




Fig. 83. Completed Mold for Core 

inside diameter. The pattern furnished was satisfactory, as was 
the half-core box, until it was found that the number to be made 
each day was gradually increasing and the number of half cores 



64 



FOUNDRY WORK 



to be dried was seriously interfering with the production of the 
regular cores required. It was decided by the foundry management 




Fig. 84. Cast-iron Arbor to Carry Core 




Fig. 85. Mold with Two Halves Together 



to adopt the use of a green-sand core, and not only relieve the core 
ovens, but also effect a considerable saving in core sand and core 



FOUNDRY WORK 



65 



binders. To make a green-sand core it was necessary to make the 
core box. The method used was as follows: 

First, a half core was made in the original box, and when this 




Fig. 86. Complete Core Placed on Horses 



was dried it was placed on a new mold board as shown in Fig. 82. 
Over this was placed lagging of the desired thickness for the casting, 
as shown in the figure; then over this were placed the loose pieces 




Fig. 87. Complete Mold with Green-Sand Core in Position 



h to form the ends of the box and part of the hinge c, also forming 
a part of hinge on drag half of box, and e and g acting as strength- 
ening ribs. 



66 FOUNDRY WORK 

With these loose pieces in position the drag was duly rammed 
and rolled over, the cope was rammed and the dry-sand core secured 
in and lifted ojff with the cope. The loose pieces were withdrawn 
from the drag, and the mold was properly finished; when closed 
and poured, this gave a satisfactory casting of the drag half of the 
core box. The cope half was made in the, same way, the only change 
being in the shape of the loose pieces forming the ends as seen 
in Fig. 83. 

An arbor being required to carry the green sand, it was made 
of cast iron, as shown in Fig. 84. To make the green-sand core, 
first riddle sand in the drag half of the core box; next place the 
arbor as shown in Fig. 83; then fill and carefully tuck the sand under 
the flanges on the arbor. The cope is simply filled with sand and 
rammed, and both drag and cope are struck off level with the joint. 
The two halves are now closed, as shown in Fig. 85, when the cope 
may be rolled back to its former position and the core removed 
from the drag half of the box by lifting an arbor extending through 
the end of the box. 

The core should be placed on horses as shown in Fig. 86, so that 
it may be repaired if necessary and blackened. Fig. 87 shows the 
complete mold with green-sand core in position. 

In this way a satisfactory core box was made without heavy 
expense for patterns, as the foundry carpenter or flask man was able 
to produce the loose pieces from a rough sketch furnished by the 
foundry foreman. 

DUPLICATING CASTINGS 

Practical Requisites in Hand Molding. Devising methods for 
increasing production and decreasing its cost is one of the important 
problems of modern engineering in the foundry as well as elsewhere. 
In the jobbing foundry where there is a great variety not only in 
the patterns themselves, but in the number of castings called for 
from each pattern, the molder makes up a sand match as already 
described. On this match he arranges such an assortment of pat- 
terns as will fill his flask, and beds them into place. From a well- 
made sand match two or three hundred molds may be made up. 
When the desired number of castings is made from one pattern 
on the match, that one is removed and another one which fits 
in its place is substituted. 



FOUNDRY WORK 



67 



Gated Patterns. For manufacturing purposes thousands of 
the same casting may be required, calling for more durable patterns 
and match. Metal patterns are made and as many as can be cast 
in a flask are soldered to a smoothly finished metal gate pattern. 
With a draw screw inserted in this gate, all of the patterns may be 
drawn at once. Two steady pins should be screwed and sweated 
into the drag side of the gate pattern. These should be of small 
round brass rod and should project below the deepest point of the 
patterns, for they guide the pattern as it is being drawn and prevent 
it from swaying and breaking the edges just as it leaves the sand. 
Patterns so arranged are termed gated 'patterns. 

Permanent Match, When such patterns have a flat joint, a 
special mold board should be provided, and the patterns stored 
on the same board. When the 
joint is irregular, a permanent oil 
match should be made. Make a 
strong hardwood frame the size 
of the flask and about 1 inch deep, 
with the bottom board arranged 
to screw on to the back. Nails 
should be driven into the inner 
sides hanging parallel to the bot- 
tom board. Measure the quan- ^''^' ^^- ^^^ ^^^"*^^ 
tity of sand needed to fill this match. Mix thoroughly and, while dry, 
put through a fine sieve one-half this quantity of burnt sand, one-half 
new molding sand, and about one-fortieth litharge. Temper the 
same as molding sand, using boiled linseed oil. Ram up the drag 
and joint the mold very carefully. Put on the match frame and 
ram up with the above mixture; strike off, and screw on the bottom 
board. Remove the drag and allow the match to dry for a day 
with the patterns left in it. A coat of shellac when dry improves 
the surface. Fig. 88 shows a set of gated patterns bedded in a hard 
match. 

Use of Molding Machines. Types. Although there are many 
styles of molding machines on the market, these may be classified 
under four general types as follows: stripping-plate machines; 
squeezers; roll overs; and jar or jolt-ramming machines. The 
benefits derived from the use of these machines are manifold. 




68 



FOUNDRY WORK 



Advantages, If no consideration were taken of the increase 
in production possible by their use, the improvement in the quality 
of castings alone would oftentimes warrant their installation, as 
the decrease in cost of machining castings produced by this method 
pays good dividends on the investment. The use of unskilled work- 
men on these machines is no small item in their favor. 

Stripping-Plate Machine. The stripping-plate machine is best 
adapted to that class of work which offers difficulties in drawing 
the pattern from the sand. 

Fig. 89 shows a pattern for a cast gear mounted on the strip- 
ping-plate machine. It is obvious 
that it w^ould require a consider- 
able degree of skill to produce this 
class of work by the hand-molding 
method. The pedestal base of 
the machine has a flat top. The 
stripping plate is supported above 
this by a rigid open framework. 
Working in guides carried on the 
sides of this framework is the draw- 
ing frame, made to rise or descend 
by a strong crank and connecting 
rod. On top of this drawing frame 
and parallel to the stripping plate 
is screwed the plate to which the 
pattern is fastened. The stripping 
plate is cast w4th an opening which 
leaves about 1 inch clear all around the pattern. When both pat- 
tern and stripping plate are properly set in place, this space is filled 
with babbitt metal, this being an' easy way to secure a nice fit. 

In many cases there may be an interior body of sand to be 
supported when the pattern is drawn. To accomplish this stools 
are used. A leg screwed into the stool plate supports the stool 
at the exact level of the stripping plate. The stool plate is fastened 
to the flat top of the machine inside of the box-like framework 
which supports the stripping plate, as seen in Fig. 90. 

A flask is inverted on the machine, rammed, vented, and struck 
off. Movement of the crank lever at the side draws the pattern; 




Fig. 89. Typical :MoIding Machine 



FOUNDRY WORK 



69 



and the mold then is removed and set on a level sand floor, tiius doing 
away with bottom boards. A second stripping plate and pattern is 
used for ramming the cope boxes. 







Fig. 90. Molding Stool with Pattern in Place 



Pulleys are manufactured on molding machines of this type, 
as shown by the equipment illustrated in Fig. 91. The rim patterns 




Fig. 91. Pulley Molding Machine 



have the form of long hollow cylinders and can readily be set for 
any desired width of face. The hub carrying the core print separates 



70 



FOUNDRY WORK 



from the spokes, lifts off in the mold, and is drawn by hand. The 
arm patterns are so flat and smoothly rounded that the mold is 




Fig. 92. Simple Molding Machine or Squeezei 




Fig. 93. Match Plate 
Courtesy of Tabor Manufacturing Company, Philadelphia, Pennsylvania 

easily lifted off of them with little fear of breaking the sand. The 
cope and drag molds are both alike for a pulley mold. 



FOUNDRY WORK 



71 



Squeezer. Fig. 92 shows a type of machine known as the hand 
squeezer, which only packs the sand. Here the patterns are carried 
on two sides of a plate set between the cope and drag, as in Fig. 93. 
Both boxes are filled with sifted sand and set on the machine. The 
boards are made to follow inside of the flask. The molder's weight 
on the lever compresses the sand. 




Fig. 94. Hand Squeezing Machine with Cope and Drag Patterns Attached to Portable Table 

Courtesy of Arcade Manufacturing Company, Freeport, Illinois 

The sprue is cut by a thin hollow steel tube called a sprue- 
cutter, which is pressed through the cope sand by the molder 
before separating the flask. In separating the mold the cope 
is first lifted from the drag, and the plate is gently rapped and 
lifted from the drag. To make a clean lift when parts of the 
patterns project in the cope, a second molder raps with an iron 
bar between the battens of the bottom board while the cope is 
being drawn off. 



72 



FOUNDRY WORK 



Such machines are used chiefly on thin work which vents and 
solidifies very rapidly — for the outer surfaces of the drag and cope 
are apt to be rammed so hard that they might choke the vent on 
heavier castings. 

A somewhat different style of hand squeezer is shown in Fig. 94, 
which shows both cope and drag pattern plates attached to a portable 




Fig. 95. Beginning the Operation with Hand Molding Machine. Two Halves of 

Flask in Position 

Courtesy of Arcade Manufacturing Company, Freeport, Illinois 



table. Beginning the operation, the table holding the plates is 
turned face up with the two halves of jthe flask in position as shown 
in Fig. 95. After the sand is thrown in the flask and the surplus 
scraped off, the bottom boards are placed in position and held by 
four clamps. Next, the table is rolled over as in Fig. 96. The 
ramming or squeezing operation is accomplished by pulling down 



FOUNDRY WORK 



73 



the long lever at the left of the machine, as shown in Fig. 97. At 
this point the clamps holding the cope and the bottom are auto- 
matically released. 

Fig. 98 illustrates the method of drawing the patterns. The 
lever is slowly lifted with the left hand, while the operator raps the 
vibrating pin with a mallet held in the right hand. When the long 




Fig.' 96. Table Rolled Over Preparatory to Squeezing 
Courtesy of Arcade Manufacturing Company, Freeport, Illinois 

lever is returned to its upright position, the two halves of the mold 
rest on the sliding platform. This is drawn forward in the position 
shown in Fig. 99. The mold is then closed, the flask removed, 
and the completed mold carried to its position on the floor for pour- 
ing. Snap flasks are best adapted for this style of machine. 

Roll Over. The roll-over machine which is illustrated by Fig. 100, 
has the pattern mounted on a wooden match plate as shown at A, 



74 FOrXDRY WORK 

which when m position to receive flask is resting on pins at BB. The 
mold is rammed by hand in the usual manner, the bottom board being 
clamped on by a special device to the frame C. The mold is next 
rolled over and rests at A. The pattern is withdrawn by the use 
of the foot pedal E, the operator meantime rappmg the match plate 




Fig. 97. Kamming or {Squeezing Oi>eration 
Courtesy of Arcade Manufacturing Company, Freeport, Illinois 



with a wooden maul. This t\'pe of machine is best adapted to side 
floor work, the grate bar here shown being a good sample. 

Power Operatio?!. The above-mentioned t^'pes show only hand 
machines which have been in general use for a considerable period 
of time, but the last decade has shown a wonderful change in this 
branch of foundry practice; indeed so great is the advance that 



FOUNDRY WORK 



75 



hardly a month passes that there does not appear some new featuer. 
The most important advancement, of course, was the adaptation of 
power, usually compressed air being resorted to, but more recently 
there has been quite a tendency to utilize electricity. 

Power Squeezer, Fig. 101 shows compressed air applied to the 
squeezer type of molding machine. This machine is designed 




Fig. 98. Drawing the Patterns. Use of Mallet 
Courtesy of Arcade Manufacturing Company, Freeport, Illinois 



especially for use in molding light snap-flask work in large or small 
quantities, and the method of pattern fitting depends upon the 
number of castings to be made from one pattern. 

A careful study of the line drawing of this machine shown 
in Fig. 102 should give a clear understanding of the working parts 
of the power squeezer, the numbered ones being identified as follows: 



76 



FOUNDRY WORK 




Fig. 99. Two Halves of Mold in Open Position 
Courtesy of Arcade Manufacturing Company, Freeport, Illinois 



1. 


Yoke 


20. 


2. 


Left-hand stop for yoke 


21. 


3. 


Yoke handle 


22. 


4. 


Pressure gage 


23. 


5. 


1-inch air cock 


24. 


6. 


Eye bolt 


25. 


7. 


Left-hand strain bar 


26. 


8. 


Right-hand strain bar 


27. 


9. 


Right-hand yoke stop 


28. 


10. 


Platen 


29. 


11. 


Knee-pad rod 


30. 


12. 


Au- hose from knee valve to 


31. 




vibrator 


32. 


13. 


Air hose from knee valve to 


33. 




supply 


34. 


14. 


Hose guard 


35. 


15. 


Knee pad 


36. 


16. 


Knee starting valve 


37. 


17. 


Cylinder base 


38. 


18. 


Piston 


39. 


19. 


Piston ring 





Counterbalance spring 

Adjustment block for spring seat 

Adjustment-block set screw 

Trunnion 

Bracket for lower spring seat 

No. 5 snap oiler 

Trunnion shaft 

Pop throttle-valve lever 

Valve-lever stud 

Throttle-stop segment 

Valve sand guard 

Valve spring for exhaust 

Adjustable strain-bar stop 

Valve body 

L hose nipple 

Straight hose nipple 

Valve bracket 

Taper pins, trunnion to shaft 

Blow valve 

Blow-valve hose 



FOUNDRY WORK 



77 



Attention is called to the fact that the production of the power 
squeezer exceeds that of the hand squeezer by 15 to 30 per cent. 
For description of various ways of mounting patterns, see Pattern- 
Making. 

Power Roll-Over. A power roll-over power-draft machine is 
shown in Fig. 103. This is designed to handle side floor work, 



^ [ 


li^^ ■ 


. rjtab-^ 




mm 


i 


1 


^^1 






'^. % 


iCr 


^-'■^-'''-'''-''^'''''''^W 


^H -^v^. |P '^^^^a,^-.^^ 



Fig. 100. Roll-Over Molding Machine with Pattern Withdrawn 
Courtesy of Tabor Manufacturing Company, Philadelphia, Pennsylvania 

and has a straight draft of 8 inches and sufficient power to roll over 
a weight of 1000 pounds. It will be noted that as in the hand roll- 
over the patterns are mounted on wooden match plates, the small 
expense of which makes this style of machine very effective in job- 
bing shops where but few castings are made from a pattern at a time. 
In Fig. 104 is shown the latest type of this machine with the 
flask shown in position ready for bar ramming. Fig. 105 shows the 



78 



FOUNDRY WORK 



mold partly rolled over; the mold rolled over and partly with- 
drawn is shown in Fig. 106. The view given in Fig. 107 shows the 
finished mold on one side and the pattern back in place. 

The working parts of the above machine are shown in Fig. 108, 
and are as follows : 

1. Roll-over frame 

2. Air cylinder 

3. Link 

4. Wedge leveling device 

5. Adjustable support for leveling device 

6. Operating valve and lever 

7. Vibrator 

The plunger is made hollow and acts as an oil tank into which 
air under pressure is admitted when the machine is to be operated. 
When air pressure is admitted to the plunger, the oil is forced through 




Fig. 101. 10-Inch Squeezer Operated by Compressed Air 
Courtesy of Tabor Manufacturing Company, Philadelphia, Pennsylvania 



FOUNDRY WORK 



79 



a port into the cylinder, causing the plunger to rise and by means 
of its link connections to roll over the mold which is deposited on 
the leveling device. After the flask has been undamped air is 
again admitted to the plunger, causing the pattern to be drawn 
vertically the full draft of the machine, at which point the link 




Fig. 102, Elevation of Tabor Squeezer Showing Working Parts 

connections cause the roll-over frame to return to its initial position 
ready to receive another flask. 

Jolt-Ramming Machine. The jar or jolt-ramming machine is 
used for all classes of work from light work up to the largest floor 
work made in green sand, the limit being only the capacity of the 



80 



FOUNDRY WORK 



macliine itself, which varies from a few hundred pounds to many 
thousands of pounds. Large engine beds are a good example of the 
castings produced on the heavy-duty machines. 




Fig. 103. Power Roll-Over, Power Draft Molding Machine with 12-Inch Straight Draft 
Courtesy of Tabor Manufacturing Company, Philadelphia, Pennsylvania 




Fig. 104. Latest Type of Tabor Molding Machine with Flask Ready for Ramming 

Patterns mounted on heavy wooden match plates are used in 
the manner hereafter described. The flask is first placed on the drag 



FOUNDRY WORK 



81 



half of the pattern board, and the flask filled with sand. By the 
use of an upset, usually about 4 inches deep, it is possible to heap 
sufficient sand on the fiask to insure its being filled after the ramming 
has taken place. The flask must be securely clamped to the pattern 
plate, when both may be listed by the traveling crane and placed 
on the table of the jarring machine, which in the heavy-duty machines 
is on the foundry-floor level; the working parts of the machine being 
below and resting on a rigid concrete foundation. Here, air under 




Fig. 105. Machine with Mold Partly Rolled Over 
Courtesy of Tabor Manufacturing Company, Philadelphia, Pennsylvania 



pressure is allowed to enter the cylinder, and, acting on the plunger, 
w^hich in turn lifts the table usually about 4 inches, when the air 
is suddenly exhausted, allows the table to drop heavily on the 
anvil. The number of blows required to pack the sand must be 
determined by experience. The time required to ram the largest 
mold is but a small fraction of that consumed by hand-ramming. 

Fig. 109 is an illustration of one of the simplest styles of this type 
of machine. Fig. 110 shows the working parts of the same machine. 



82 



FOUNDRY WORK 




Fig. 106. Mold Completely Rolled Over and Partly Withdrawn 
Courtesy of Tabor Manufacturing Company, Philadelphia, Pennsylvania 




Fig. 107. Finished Mold on One Side and Pattern in Place 
Courtesy of Tabor Manufacturing Compatiy, Philadelphia, Pennsylvania 



FOUNDRY WORK 



83 




Fig. 108. Diagram of Working Parts of the Tabor Molding Machine 




Fig. 109. Simple Type of Jolt-Ramming Machine 
Courtesy of American Molding Machine Company, Terre Haute, Indiana 

A quite distinct style of jolt machine, called an electropneumatic 
jolt-ramming machine, is shown in Fig. Ill, the unique feature 
being the motor-driven compressor without a clutch, spring, cam. 



84 



Table 



FOUNDRY WORK 

■Z Sn cased (^uide Fins 



^SafGttj Bolt 

Space arOQnd 
■F'iston 




Fig. 110. Section of American Jolt-rtaraming Machine 




Fig. 111. Krause Electropneumatic Jolt Rammer 
Courtesy of Vulcan Engineering Sales Company, Chicago, Illinois 



86 



FOUNDRY WORK 



or valve. A very little study of Fig. 112 should make clear its 
radical features. 

Automatic Squeezer. Fig. 113 illustrates an automatic molding 
machine of the squeezer type. The operator places the flask and 
bottom board in position, then by simply pressing on the starting 
lever the filling of the flask with sand, the ramming and the drawing 
of the pattern is completely automatic and accomplished in about 




Fig. 113. Automatic Molding Machine of the Squeezer Type 
Courtesy of Berkshire Manufacturing Company, Cleveland, Ohio 



eight seconds or some six or seven hundred molds per day. This 
machine is best adapted to the production of small duplicate work 
such as small pipe fittings. 

Roller-Ramming Machine. The very distinctive type of mold- 
ing machine shown in Fig. 114 is known as the roller-ramming 
machine. It is best adapted to long work of comparatively thin 
cross-section, of which a cornice section would be a good example. 
This class of work could not be produced readily on any of the 



FOUNDRY WORK 



87 



previously mentioned types of machines. Fig. 115 is a detailed 
drawing of Fig. 114. 




The success of any and all molding machines depends on the 
intelligent selection of the type best suited for the work in hand. 




•??c3q 



FOUNDRY WORK 89 

DRY=SAND WORK 

Characteristic Features. This branch of molding becomes 
a separate trade in shops where the work is done continually. The 
dry-sand molder must use the same precautions as the green-sand 
molder in setting gates and risers, and in fastening his sand with 
crossbars and gaggers. At the same time, he works with a core- 
sand mixture next his patterns and backs this with a coarse molding 
sand, so that he must combine the skill and judgment of both the 
green-sand molder and the core maker. The venting of dry-sand 
work must be ample, as in the case of cores, but it is simpler than 
in core work, because the core mixture surrounds the casting so that 
vents may be taken off in all directions. 

Iron flasks are used, generally provided with trunnions to 
facilitate turning. The facing mixture is the same as that used 
for making large cores, as discussed in the section on Core Work; 
the remainder of the flask is packed with the same sand after it has 
been used. The patterns are made and used the same as with green 
sand, only they should be brushed over with linseed, crude-oil, 
or other heavy oil, before ramming. In some shops oil is brushed 
over the joint before parting sand is thrown on. After the pattern 
is drawn, the mold is finished by applying a heavy coat of good black 
wash. When the sand has absorbed the moisture so that all glisten 
has disappeared, this blacking is slicked over. Great care must 
be exercised in this operation, for too much slicking will draw the 
moisture to the surface again and result in scabs on the casting. 

Molding Engine Cylinder. Engine cylinders are a representative 
line of work for dry sand. Consider a simple type of cylinder, 
such as shown in Pattern-Making, Fig. 244, to have a bore of from 
16 to 26 inches, and with the exhaust-outlet flange placed above 
the center of the cylinder. To facilitate setting the cores, the pat- 
tern may be split through the steam chest. The flange just men- 
tioned should be molded in the drag, and should be made loose 
and draw in the opposite direction from the main pattern. The 
cylinder core should be made on a barrel, as will be explained later, 
and the mold poured on end to insure sound metal and to reduce 
the casting strain on the port cores. The flask is made with a 
round opening in one end to allow the core to project through it. 
This opening is larger than the diameter of the core to allow for 



90 



FOUNDRY WORK 



gates and risers. There must be another opening at the side of 
the flask adjacent to the steam-chest core to provide for fastening 
these cores. Iron plates serve for flask boards and there should 
be a hole in the drag plate in line with the exhaust core to allow for 
venting and fastening its end. 

One-half of Fig. 116 shows the end view of the flask. The 
other half shows a section through the middle of the completed mold. 
Here A is the hollow cylinder core, B is the chest core, C the live- 
steam core hung in the cope, and D the exhaust core. The flask 
is packed in a manner similar to green sand. 

Use of Cover-Core. The method of molding the exhaust 
flange, however, has not previously been explained. To do this, 




Fig. 116. Molding a Cylinder 



proceed packing the drag until the pattern is covered. Tuck tl 
facing carefully underneath the flange, setting in rods as in core work, 
to strengthen the overhanging portions. Make a flat joint, FC 
at the level of the top of the flange, then carefully fit over the prii., 
of the flange the cover-core E, and fix its position with nails driven 
into the joint at its corners. Now remove the cover-core, draw 
the flange, and finish that part of the mold with black wash and 
slicking. When this is accomplished, replace the cover-core, place 
a short piece of pipe over its central vent, and finish ramming the 
drag. This method may be used in many cases, both in dry-sand 



FOUNDRY WORK 



91 



and in green-sand work where a small detail of the casting requires 
a separate joint surface. 

A sectional plan looking down on the drag is shown in Fig. 117. 
When the mold has been properly finished and baked, the drag is 
brought from the oven and set on a pair of stout horses. The 
cylinder core is first set in place, then the exhaust core is set in its 




Fig. 117. Sectional Plan of Fig. 116 Looking Down on Drag 

drag print and held close to the cylinder core, while the port and 
chest cores, previously pasted and fastened, are lowered into the 
chest print. The chest print is cut a little long at aa, to allow its 
core to be drawn back slightly, while the exhaust core is entered 
into its place between the port cores. Then all of the cores are set 
forward into position, the chaplets bb set, the space aa tightly packed 
again, and the anchor bolts cc placed in position and made fast. 



92 



FOUNDRY WORK 



The drag print of the exhaust core is made fast from underneath 
the drag plate. When all the cores have been firmly fastened, 
the cope is closed on, and the two boxes clamped at the flanges 
and set up on end. The runner. R and the riser S were cut and 
finished before baking; the basins must be built in green sand after 
the mold is closed. 

Making Barrel Core. Loam is used here for the outer shell 
of the core. It is probably the simplest job in which a loam mix- 
ture is employed, and is made by a core maker more frequently 
than by the higher paid loam molder. Barrel cores are used where 
the core is long and can best be supported at the ends only; for 
example, in gas and water pipes and cylinder work. 

Loam. Loam is a facing mixture, of the consistency of mortar, 
applied to the face of the core or mold. It contains fire sand with 
a bond of strong porous molding sand moistened with a thick clay 
wash. A small proportion of organic matter in the shape of horse 
manure is put in to aid the bond and to leave the crust of loam more 
fragile by burning out as the casting cools. Proportions of the 
mixture will vary according to locality, but the principles already 
cited hold here as with other molding compounds. With too much 
bond the loam works easier but tends to choke the vents when 
casting. With not enough it is weak and is liable to break, cut, 
or crumble under strain. A typical mixture is as follows: 

Loam Mixtures 



Material 


Mixed by Hand 
(parts) 


Mixed by Miti 
(parts) 


Fire sand 

Strong coarse molding sand 

Horse manure 


10 

4 


10 
3 

2 


Temper 


Thick clay wash 


Thick clay wash 



The advantages of loam cores are that they are lighter, cheaper 
to make, and carry off the gases faster than do dry-sand cores. 

Method. The method is as follows: A piece of pipe about 
3 inches smaller than the outside diameter of the core is selected 
to form the center. The pipe is perforated with a large number 
of holes. If the pipe is more than 3 or 4 inches in diameter, centers 



FOUNDRY WORK 



93 



or trunnions are riveted in the ends to serve as bearings. The pipe 
is arranged to revolve freely on a pair of iron horses, as shown in 
Fig. 118. A crank handle is attached by which the pipe may be 
turned. A couple of wraps of hay rope are first given around one 
end of the pipe, and the loose end is pinned flat by a nail run under 
these strands. Tight wrapping is then continued to the other end 
of the pipe, where the rope is fastened in a similar manner and cut 
off. Hay rope should be made of long wisps tightly twisted. Sizes 
vary from f to 1 inch. Where only a small amount of hay rope 
is used, it is bought ready made. Foundries using large quantities 




Fig. 118. Making Loam Core for Cylinder 



are equipped with one or more machines built especially for making 
this rope. 

The first coat of loam is rubbed on with the hands, then well 
pressed in with the flat side of a board as the barrel is slowly revolved. 
When this has set, the core board A is placed in position, and the 
roughing coat worked on to the core to within about i inch of 
finished size. The core is now dried in the oven. Placing the core 
again on the standards, the finishing coat of slip is applied with the 
core board while the core is still hot. The diameter is tested with 
calipers and brought to required size by slight adjustment of the 
sweep board A. When the core has been built to size, move the 
loam back from the edge of the board A, then withdraw the board 
while the barrel is still in motion. 



94 FOUNDRY WORK 

Slip. Slip or skinning loam is made by thinning regular loam 
as it is rubbed through a No. 8 sieve. The heat of the core is usually 
sufficient to dry this slip coat enough so that black wash may be 
brushed on and slicked, as in dry-sand work, before running the 
core into the oven again for its final baking. 

The service of the hay rope on a barrel core is twofold: it fur- 
nishes a surface over the smooth metal of the barrel to which loam 
will adhere; and it is elastic enough to give as the casting shrinks 
around the core. The hay slowly burns out after the casting has 
set, and this frees the barrel so that it can easily be withdrawn and 

used again. 

LOAM MOLDING 

Skill Required. The loam molder requires the greatest all- 
around skill in the whole range of foundry work. He must know all 
the tricks of the core room and dry-sand shop, and most of those in 
green sand. Added to all this he must have a practical working 
knowledge of the principles of drawing and must possess to a large 
degree the foresight of the designer. 

In order to save time and lumber in the pattern shop, only a set 
of sweeps is provided if the mold is simple, and these, with blue 
prints of the piece wanted, are all the molder has to work from. In 
intricate work, such as a modern Corliss cylinder, a skeleton pattern 
carrying the steam chests, etc., in accurate position is made, and in 
some very crooked work a pattern is furnished complete. As a rule, 
however, the loam molder must rely upon his own skill and ingenuity 
for the best method of constructing each detail of the work. 

Rigging. The equipment for the loam floor varies in different 
shops. In Fig. 119 are shown the essential features of an equipment 
for sweeping-up circular forms. 

Spindle. The spindle a should be large enough not to spring 
when being used, and long enough to conveniently clear the highest 
mold. A piece of 2-inch shafting is a handy size, for with it the sweeps 
may be made uniformly 1 inch less than the required diameter and 
placed snug to the spindle when set up, and the correct size of mold 
is ensured. This spindle should revolve smoothly in a step b. The 
step shown may be set at any convenient place on the floor. It has 
a long taper bearing, as shown in section A, capable of holding a 5-foot 
spindle without need of any top bearing. The three arms serve to 



FOUNDRY WORK 



95 



make the step set firmly, and upon them any plate may be readily 
leveled up. Where a tall spindle is used, the spindle socket is more 
shallow; the step may be cast without arms and be bedded in the 
floor. The top of the spindle is steadied by the bracket c. This 
must carry a bearing box so designed that the spindle may be readily 
set in position or removed. And the bracket must swing back out of 
the way when any parts of the mold are to be handled by the crane. 
8-iveeps. The sweeps are attached by means of the sweep arm d. 
The detail B shows one method of clamping the sweep arm to the 
spindle by using a key. The arm is offset so that one face hangs in 




Fig. 119. Rig for Loam Work , 

line with the center of the spindle. Bolting the face side of the sweep 
to this brings the working edge in a true radial plane. Sweeps are 
usually made from pine about 1| inches thick. The working edge 
is cut to the exact contour of the form to be swept, and then is 
beveled so that the edge actually sweeping the surface is only about 
f inch. For very accurate work or when sweeps are to be much used, 
the edge is faced with thin strap iron to prevent wear. 

Plates. We have seen that the walls of green- and dry-sand 
molds are supported by sand packed into flasks and that these flasks 
may be lifted, turned up sideways, or rolled completely over to suit 



96 



FOUNDRY WORK 



the convenience of the workman. The facing which forms the wall 
of a loam mold is supported by brickwork built upon flat plates of 
cast iron, and laid in a weak mortar of mud. From the nature of their 
construction, therefore, these molds must always be kept perpen- 
dicular when being handled. The parts may be raised, lowered, or 
moved in any direction horizontally, but they must not be tipped or 
rolled over. 

The plates are cast in open sand molds, as illustrated in Fig. 56. 
Two methods are employed to provide for handling them by the crane; 




Fig. 120. Laying-Up Loam Work 

either lugs are cast on the edges of the plates, as in C, Z), and E, 
Fig. 119, or wrought staples are cast in the plates, as shown in B, 
Fig. 120, or in the crown plate of the main cylinder core, Fig. 123. 
Three typical plates for a loam job are shown in Fig. 119. 
C is the building plate; it should be at least 18 or 20 inches larger 
than the largest diameter of the casting to be made, and thick enough 
to support the weight of the entire mold without springing. D shows 
a cope ring; its inside diameter should clear the casting 2 inches 
on all sides. The face should be 8 to 12 inches wide, depending upon 



FOUNDRY WORK 



97 



the height of the mold. E shows a cover plate; its diameter equals 
the outside diameter of the brickwork on that part of the mold which 
it covers. Here the loam facing is placed directly on the iron, and 
must be supported when the plate stands vertically or is turned com- 
pletely over as in C, Fig. 122. To hold the loam in this way, fingers 
or stickers are cast on these plates. This is accomplished by simply 
printing the end of a tapered stick into the bed of the open mold which 




Fig. 121. 



Steps in Sweeping Up Tj^pe Mold 



shapes the plates. These sticker plates are often used for a purpose 
similar to the core E, Fig. 116, and shape the outer face of a picked- 
out flange. This is illustrated in J), Fig. 122. 

Materials. Brick,. Common red brick is best for making loam 
molds, Figs. 120 to 123. It should be free from glaze and have a 
uniform texture, so that the pieces will break clean when it is 
necessary to fit them to the shape. An old 12-inch half-round file 
makes a handy tool for cutting these. Sometimes brick is molded 



98 



FOUNDRY WORK 



up from loam, and air-dried. It is much more fragile than red 
brick, and may be used in pockets, or where the shell of the casting 
is quite thin, and ordinary brick might resist the shrinkage strain 
to such an extent as to endanger cracking the casting. 

Mud, For laying up the brickwork, mud is used, loam facing 
being applied only to those surfaces which come in actual contact 




ConsTructfon of Moid 
at A/02Z/e-D- 



'Stnng 




m- 



Spider 




Fig. 122. Complete Typical Loam Mold 



with the iron. Mud is made from burnt loam or old floor sand, mixed 
with clay wash to the consistency of mortar. 

Facing. The composition of loam facing and slip have already 
been given under the description of making a barrel core. 

Cinders. Cinders are an important material in this work. Their 
size will depend upon their position in the mold. For working in 
between brick, the cinders should be crushed if necessary, put through 
a No. 4 sieve to remove smallest pieces, then passed through a No. 2 
sieve to remove the larger pieces. 



FOUNDRY WORK 



99 



Principles of Work. Parts of Mold. The names of the main 
parts of a loam mold differ somewhat from those applied when molding 
in flasks. As will be seen from the section, Fig. 122, there are three 
main divisions in the mold: A, which corresponds to the drag in a 
three-part mold, is called the core. By which corresponds to the cheek, 
is called the cojpe in loam work. And C, which serves the same purpose 
as the cope of a green-sand mold, is spoken of as the cover in loam 
molding. W hen the central core is actually made a separate piece, 
as in Fig. 123, the lower part of the mold is called the bed or foundation. 



FLOOR 




Fig. 123. Loam Mold for Marine Cylinder 



Laying-Up. In laying-up a loam mold. Fig. 120, set the 
plate central with the spindle and approximately level. Then set 
the sweep and finish leveling the plate until repeated measure- 
ments at the four quarters of the circle show a uniform space 
between the lower edge of the sweep and the surface of the plate. 
For the building plate this measurement should be 5 inches; for a 
sticker plate the sweep should clear the sticker points by J to 1 inch 
according to the thickness of the casting. 

The hands are used in spreading mud or loam upon the plates 
or brickwork when building the mold. The brick must always be 
set well apart, leaving a space at least the width of a finger between 
them. Fill in these spaces with fine cinders. The reason for this is 



100 FOUNDRY WORK 

fourfold. It facilitates drying ; it provides good vent ; it gives or crushes 
sufficiently when the casting shrinks not to cause undue strain; 
and it reduces the labor in cleaning. In each course of brick the 
joints should lead as directly as possible away from the casting, but 
the joints should be broken between courses. These points are illus- 
trated in the sketch A, Fig. 120. As shown, the first two courses of 
the core are usually set edgewise. For the rest of the core and for the 
cope, the bricks are laid flat. These bricks run lengthwise around the 
circumference, with a course of headers about every four to six 
courses. 

Venting. Cinders between brick form the ordinary means of 
leading the vent from the loam facing. In confined places or pockets, 
as, for example, between the flange D and the main casting, Fig. 122, 
additional provision is made by laying long wisps of straw between 
the courses of brick. The service of the straw is similar to that of 
the hay rope of a barrel core. 

Jointing, The joint in loam work is made by a plate lifting away 
from a loam seat, or by two loam surfaces separating one from 
another. In forming the first of these the loam seat is swept up and 
allowed to partially set, then the surface is brushed with oil, and part- 
ing sand is thrown over it. The seat should then be soft enough to 
allow the iron plate to sink into it sufficiently to find a good bearing, 
while the oil and parting sand will prevent the loam facing from 
adhering to the underside of the plate. For the loam-to-loam joint, 
the same method is used, but the loam is allowed to set somewhat 
harder before building the joint against it. The angle of the main 
joint should be about 1 in 4 inches. 

To insure the different parts being put together for casting in 
exactly the same position in which they were built, a guide surface of 
loam is smoothed across the joint at three or four convenient points 
on the outside walls of the mold. These surfaces are each marked 
differently with the edge of the trowel, similar to the cut at C, 
Fig. 120. 

Drawback. To properly separate and finish some molds, it is 
necessary to lift away a portion of the mold before lifting the main 
part. Such a portion is called a drawback. The drawback is always 
built up in position against a pattern or sweep. With the cover 
plate, which on a smaller scale often serves the same purpose, as at 



FOUNDRY WORK 101 

D, Fig. 122, a flat joint is made on the outer wall of the mold, but the 
cover plate is swept up separately. At 3, Fig. 123, is shown a 
drawback which carries but a few courses of brick. It may be lifted 
away by lugs cast in the drawback plate with little danger of dis- 
placing its brickwork in handling. 

If the shape of the drawback renders it impracticable to handle 
it by the lower plate alone, the brickwork should be bound together 
by means of hook bolts which clamp on a top plate set sufficiently 
below the upper joint to be entirely protected from the metal. This 
upper plate has staples cast in it by which the whole drawback may 
be lifted. At 5, Fig. 120, the typical construction of such a piece is 
illustrated. The drawing shows one-half the length of the brickw^ork 
removed to bring out more clearly the rigging used. The upper 
end of the second lifting staple shows at a, with the loam cut neatly 
away to allow hooking into the staple. 

Where the main core lifts away or is to be covered with metal 
over its top, it must be bound together in a similar manner. This is 
illustrated in the mold for the marine-engine cylinder. Fig. 123, in 
which both of these conditions occur. 

Example of Internal Flange, If a casting has an internal flange 
requiring thickness of metal underneath the main core, the rigging 
will be altered to fit these conditions, as shown at D, Fig. 120. In 
this sketch a is a sticker plate and so will carry the loam necessary 
to face the bottom of the core. To this the small bearing plate h is 
securely bolted by the hook bolt c. This plate must set directly upon 
solid brickwork, as it carries the w^eight of the entire core. On this 
bearing plate are cast three studs which firmly support the sticker 
plate at the required height above the flange surface. The sticker 
plate carrying this print is filled with loam or dry sand and given a 
first baking, then swept to a finished surface before being inverted 
into position. Then the remainder of the core is built up on top and 
bound together, as in the previous example. Another way to form 
the bottom of this core is to sweep up a dummy flange dy in mud. 
Set the bearing plate h, and work the loam in around the studs to 
form the short neck to the level of the top of the flange. Then 
spread over this flange J inch of loam and bed down onto this the 
sticker plate which has been previously filled with loam and dried, 
as is described below. Be sure that the studs on h bring up to a 



102 FOUNDRY WORK 

firm bearing against the plate a, then clamp tight with hook bolts 
and proceed to sweep-up the body of the core. 

Bedding Cover Plate, In case a cover plate must be bedded down 
against a flat surface, as in the example just mentioned, or must 
take the impression of an irregular surface on the top of a mold or 
pattern, as illustrated in Fig. 123, the method to pursue is as follows: 
After casting, invert the plate and carefully lower it into position, 
and make sure that all fingers clear the surface by at least f or f 
inch. Now set the plate with the fingers up, fill in with loam enough 
to just clear their tops, leaving the proper openings for runners, risers, 
tie bolts, etc., and dry thoroughly in the oven. Upon removal 
from the oven, invert and try this loam cover again on the surface 
it must fit; scrape away any portions which project too much. Ndw 
hoist away the cover and coat the face with clay wash. Having 
previously prepared the surface of the pattern with oil and any 
loam joint with oil and parting sand, spread an even thickness of 
fresh loam all over and bed the plate down upon this. The cover 
plate, being still hot, will, by the aid of the clay wash, cause the 
thin layer of fresh loam to dry out and stick fast to the dry loam 
forming the body of the plate. 

Simple Mold. As an example of a simple loam mold let us 
consider the details of a large casting, having the shape of the 
frustrum of a cone, with a flange at the top and bottom and a 
flanged nozzle projecting from one side, such as the section clearly 
shown in Fig. 122. 

Foundation. Set the sweep, level up the building plate, and, 
building the brickwork as shown in A, Fig. 120, sweep the seat, joint, 
and bottom surface of flange, as shown at A, Fig. 121. The lower 
flange may be formed by a wooden pattern furnished by the pattern 
maker, but it is more common to have the sweep made with the 
small board x, w^hich may be removed. By doing this the exact shape 
of the flange may be swept up without changing the main sweep, 
as shown at B, Fig. 121. This dummy flange, as it is called, is swept- 
up from fairly stiff mud. 

Cope. The next step is to seat the cope ring and set the cope 
sweep, as shown at C, Fig. 121. This sweep shapes the mold for the 
outside of the casting, for the top flange, and for the top joint of the 
mold. Loam is thrown, a handful at a time, against the joint and 



FOUNDRY WORK 103 

dummy flange, and the engaging faces of bricks are rubbed with 
loam and pressed into position. 

When the top of the lower flange is reached in this way, the 
courses are laid-up for about 2 feet before the loam is spread upon 
their inner surface and struck off. This method is pursued until the 
mold is built to its full height. 

The projecting nozzle is formed by a wooden pattern; this should 
be well oiled, and the brickwork and loam laid-up under it to support 
it at the proper level, as given by the center line on the pattern and 
corresponding line on the sweep. Such projections frequently must 
be supported in their exact position with reference to the main 
pattern by temporary wooden framework or skeleton work until 
the mold is built up under them. 

A finger y nailed to the top member of the cope sweep, shapes the 
guide surfaces on the outside of the mold which are used to center the 
cover plate in closing the mold. A similar finger exactly the same 
distance from the spindle, is fastened to the sweep used to form the 
cover plate. 

After the finishing coat of slip has been swept on the surface of 
the cope, a joint surface about 4 inches wide is struck off flush with 
the outer face of the nozzle and that pattern is drawn out. 

Then the whole cope is lifted off and set on iron supports where it 
may be conveniently finished with black wash and slicks. It is then 
baked over night in the oven. 

Center Core, The dummy flange is now entirely removed from 
the first part swept, the core sweep is set, D, Fig. 121, and the 
center core is strilck up. This core is then blackened, slicked off, and 
baked. The cover plate is struck off with the stickers up, and baked 
so. This cover carries six 1-inch round holes through it, which will 
be just over the shell of the metal when the mold is closed. Five of 
them connect with the pouring basin and serve as runners, while 
the sixth serves as a riser. 

Closing. In assembling the mold for pouring, the core is first set 
on a level bed of sand, the cope is accurately closed over it by the 
aid of the guide marks, and lastly the cover plate is closed in position. 
Now the whole mold is firmly clamped by blocking under the spider, 
from which wrought-iron loops or strings connect under the lugs of 
the building plate, as shown in Fig. 122. 



104 FOUNDRY WORK 

The small core for the nozzle is now set, resting on stud chaplets. 
The cover plate D is slid over the end of this core and thus holds it 
firmly in position. 

The casing is now placed around the mold and molding sand 
rammed in to support the bricks against the casting pressure. At the 
level of the nozzle core cinders are placed, and a pipe leads off to 
carry away the vent gases. The sand is rammed to about 12 inches 
over the cover plate and in it are cut the channels connecting the 
pouring basin and runners. A couple of bricks are set in the bottom 
of the basin to receive the first fall of metal from the ladle. 

Pouring. In pouring, the runners must be flooded at once and 
kept so until the mold is full. 

In heavy cylindrical castings it was formerly thought necessary 
to carry the shell of the casting some 6 inches higher than the top 
flange. This head served to collect ^.11 dirt and slag that perchance 
entered the mold with the iron, and it was cut off in the machine shop 
and returned to the foundry as scrap. With the increased knowl- 
edge of iron mixtures this head is now done away with in most 
instances. 

Where a large casting is to finish practically all over, and very 
clean metal is therefore necessary, overflow channels, connecting with 
pig beds, are often constructed in modern practice. Then, when 
pouring, the metal is not stopped until a certain per cent of it has 
been flowed entirely through the mold. This of course tends to wash 
out any dirt which may have gotten into the mold when pouring 
began. 

When the casting is cold, the casing and packing sand as well as 
the blocking under the spider are removed. Then the whole mold is 
carried to the cleaning shed where the bricks are removed and the 
casting cleaned. 

Intricate Mold. As an example of a complex piece of loam work, 
let us consider the molding of a modern marine-engine cylinder, as 
shown in section. Fig. 123. The example given is that of a double- 
ported low-pressure cylinder of a triple-expansion type. In this 
case a full wooden pattern should be built, with core boxes for the 
various dry-sand cores that enter into the construction of the mold. 

Foundation. The limits of this article prevent a detailed discus- 
sion of this subject; we will, therefore, confine ourselves mainly with 



FOUNDRY WORK 105 

an explanation of the drawing, Fig. 123. The heavy building plate 
has a spindle opening somewhat to one side of its middle to be under 
the center of the cylinder. Upon this building plate the foundation 
of the mold is swept, carrying the seat for the cope ring, the bottom 
face of the flange, and the seat for the main cylinder core. The cope 
ring 1 is made wide enough on one side to carry that part of the 
mold forming the steam chest. The main cylinder core 2, the 
construction of which has already been explained, is next swept-up 
and lifted away, finished, and baked. 

Cope. Now the cope ring is seated, and the mold built and struck 
off for the bottom of the steam chest on a level with the bottom face 
of flange. Then the pattern may be set. Its position- is accurately 
determined by the main cylinder print and the smaller prints of the 
steam chest which are bedded into the loam in accordance with 
measurements along a radial line marked off on the loam surface. 
With the pattern well oiled, the cope is built to the height of the upper 
flange of the cylinder; the entire back of the steam-chest core print 
being left open. The top of the steam chest is lifted off with the 
drawback S, which joints at the middle of the upper steam nozzle, 
and carries that part of the mold to the level of the main cope joint. 
The two steam nozzles and the exhaust nozzle may be made with 
separate cores as explained in B, Fig. 122. By using the drawback, 
the entire top of the chest core print is left open for convenience in 
setting the chest and port cores. 

The top of the cylinder is jacketed, and through it pass the 
stuffing-box and manhole openings. The flanges of these two open- 
ings connect and in the pattern are left loose. The whole top surface 
is so irregular that it requires three levels of sticker plates to mold 
it, aside from two small cover plates over flanges. 

Covers, To the main cover Jf. 4 4 4 with its various lengths 
of fingers, is bolted a crab 5 5 5 to carry the loam below the flanges 
of the stuffing box and manhole; and below this again are hung the 
dry-sand cores, 8 8 8, forming the jacketed part of the cylinder 
head. On top of the main cover is fastened a separate plate, 6, 
to shape the top of the upper steam inlet. And at 7 a plate with 
wrought-iron bars cast along its edge carries the loam back of the 
steam-chest flange. The small cover plates, 9 and 10, allow the 
flanges to be drawn for the parts which they mold. 



106 FOUNDRY WORK 

The pattern is made in many parts so as to properly draw from 
the mold. When this has been done, all mold surfaces are carefully 
blackened and slicked before baking. 

Coring. While the mold proper is being built, the dry-sand 
cores should be made up by the core makers, with the necessary rods, 
hangers, vent cinders, etc., as described under Core Making. 

The manhole core, 11, h made with a stop-off piece in the 
box to give the proper angle at the bottom of the core. It is hung to 
the cover and clears the main core by \ inch. The stuffing-box core 
rests in a print in the main cylinder core, and is held by a taper print 
in the cover plate 10. 

The jacket cores are hung as shown. The openings made in the 
loam above the crab, to allow the hook bolts to be drawn up tight, 
are stopped off with green sand as previously described. The inlet 
cores 12 12, the exhaust core, 13, and the lightening cores, IJf 14 14, 
are all bolted directly through the steam-chest core, 15, to horizon- 
tal bars which are long enough to bear against the sides of the mold 
at the back. The upper inlet core, 12, is kept from lifting under the 
pouring strain by being bolted to the body of the main cylinder core. 
Stud chaplets are also set between the inlet and exhaust cores to 
ensure correct thickness of metal at these points. 

Venting. The vent is taken off from the main cylinder core 
through the stuffing-box core at the top. Sometimes a small ladle- 
ful of metal is poured through this opening, when the piece is being 
poured, to ensure lighting these gases. The vent for the series of port 
cores is taken off by ramming a cinder bed up the entire back of the 
steam-chest core, allowing the gases to escape at the top. For safety, 
also, vents are taken from the bottom of the port and chest cores 
by the usual pipe vent. 

Pouring. The provision for pouring this mold requires especial 
attention. Notice the construction of the main basin, 16. The long 
runner 1 7, leading to the bottom gate, is left open on one side when 
the mold is built, so that it may be easily finished and kept free 
from dirt. Its open side is closed by cover cores when the mold is 
rammed up. 

Ten or twelve small gates like 18 are connected with the 
pouring basin, by semicircular channels, but are so placed that no 
metal shall fall on a core. With the basin arranged as shown, the 



FOUNDRY WORK 107 

bottom part of the mold is first flooded with iron. When this has 
been done, the metal is poured in faster, so that hot iron is well 
distributed around the shell of the casting through the small top 
gates. Should the mold be poured at first from these top gates, the 
fall of the iron through the full height of the cylinder to the lower 
flange might result in cutting the loam on that surface. 

Molds of this size are usually rammed in a pit so as to bring the 
pouring basin conveniently near the floor. The portion above the 
floor level is, of course, rammed inside a casing, as described in the 
previous example. 

To guard against uneven cooling strains in this intricate casting, 
the clamping pressure on the mold is relieved when the metal has 
solidified, but the sand is not removed from around the brickwork for 
several days. This allows very gradual even cooling. 

It will be noticed that the piston does not work directly upon the 
inner walls of this type of cylinder. A separate hollow shell or lining 
is cast of strong tough iron. This has outside annular ribs at top 
and bottom and middle, which are turned to fit correspondingly pro- 
jecting ribs seen on the inside of the casting just under consideration. 
An air space is thus left between the lining and main casting which 
forms a jacket around the bore of the cylinder. 




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FOUNDRY WORK 

PART II 



CASTING OPERATIONS 

MELTING 

General Characteristics. The subject of melting the metal 
which is to be poured into molds is one of the most important con- 
siderations in the foundry. It is also one which has received much 
attention in the last few years, the endeavor being to get away from 
the old rule-of-thumb methods and to arrive in the iron foundry 
at something near the precision in resulting metal that is already 
attained in the brass shops or the steel foundry. 

The heat for all melting is obtained from practically the same 
two chemical elements — carbon, and oxygen — carbon coming from 
the fuel, be it coal, coke, oil, or gas; and oxygen coming from the 
air of the blast. 

The design of the furnace, the kind of fuel used, and the applica- 
tion of the blast vary in accordance with the peculiar properties of the 
different metals and the degree of heat required to melt them. 

The melting of steel, copper alloys, and malleable cast iron will 
be dealt with under separate headings. We shall now consider only 
the melting of gray foundry irons. 

CUPOLA FURNACE 

Furnace Parts. Foundry iron is melted in direct contact with 
the fuel in a cupola furnace. The name was derived from the resem- 
blance of the furnace to the cupola formerly very common on the 
top of dwelling houses. 

Bottom. The cupola consists of a circular shell of boiler plate, 
lined with a double thickness of fire brick and resting on a square 
bedplate, with a central opening the size of the inside of the lining. 
This bottom is supported some 3^ feet above a solid foundation, on 
four cast-iron legs. The bottom opening may be closed by cast-iron 
doors, which swing up into position, and are held so by an upright 




Fig. 124. Section Through Modern Cupola Furnace 



FOUNDRY WORK 111 

iron bar placed centrally under them. These doors, protected by a 
sand bed, support the charge during the heat, and drop it out of the 
furnace when all the iron has been melted. The legs curve outward 
and the doors are hinged as far back as possible to protect them as 
much as can be from the heat of this ''drop". 

Breast. At one side, level with the bottom, is the breast opening, 
at which place the fire is lighted, and in which the tap hole is formed 
for drawing off the melted metal. The spout, protected by a fire-sand 
mixture, projects in front of the breast and guides the metal into 
the ladles. 

Slag Hole. On cupolas over 36 inches inside of the lining, a 
slag hole is provided, which is similar to the tap hole, and is placed 
opposite the spout and about 2 inches lower than the main tuyeres. 
Fig. 124 shows a section through a modern cupola furnace, and needs 
but little further explanation. 

Lining. In lining the stack, the layer next the shell is usually 
made of boiler-arch brick about the size of regular fire brick. These 
are set on end, and should be fitted as tightly together as possible, 
and laid in a thin fire cement, made of very refractory fire clay 
and fine sharp silica sand. The object is to fill every crevice with a 
highly refractory material. Specially made curved fire brick can be 
purchased for the inside lining, although some foundrymen use the 
arch brick for this lining as well. The lining over the tuyeres is shaped 
to overhang them slightly, to prevent melted slag dropping into them 
during the heat. The lining burns out quickest about 22 inches 
above the tuyeres, at what is practically the melting zone. The angle 
shelves riveted to the shell, as seen in the illustration, allow this 
section of the lining to be renewed without disturbing the rest of 
the stack. 

Tuyeres. The oblong air inlets, called tuyeres, are placed about 
12 inches above the bed, and connect with an air-tight wind box 
which surrounds the outside of the stack near the base. The tuyeres 
direct the blast into the fuel, increasing the heat sufficiently to melt 
the charge. In the wind box, opposite each tuyere, is an air-tight 
sliding gate with a peephole, which allows the melter to look directly 
into the furnace. 

In the larger cupolas a second set of tuyeres is arranged about 
10 inches above the main ones. They are used, when long heats are 



112 



FOUNDRY WORK 

TABLE III 
Sizes of Cupola Furnaces 



Diameter 

Inside of 

Lining 

(inches) 


Cupola 
Height 

(feet) 


Chaeging Dooe 

Size 

(inches) 


Melting Capacity i 


[Per Hour 

(tons) 


Per Heat 

(tons) 


18 
20 
24 
30 
40 
50 
60 


6 to 7 

7 to 8 

8 to 9 

9 to 12 
12 to 15 

15 to 18 

16 to 20 


15 by 18 
18 by 20 
20 by 24 
24 by 24 
30 by 36 
30 by 40 
30 by 45 


ito f 
h to 1 

1 to 2 

2 to 5 
4 to 8 
6 to 14 
8 to 16 


1 to 2 

2 to 3 

3 to 5 

4 to 10 
8 to 20 

15 to 40 
25 to 60 



run off, to make up for loss of wind caused by the main tuyeres 
becoming partially choked by slag. 

The height of the tuyeres above the bed varies with the class of 
work to be poured. Where the metal is tapped and kept running 
continuously and is taken away by hand ladles, as in stove-plate 
work, the tuyeres are as low as 8 inches or 10 inches above the bed; 
while in shops where several tons of metal may be required to fill 
one mold, the tuyeres are as high as 18 inches above the bed. The 
height of the spout above the molding floor also varies in the same 
way; for hand-ladle work it may be but 18 inches above the floor, 
while a height o^ 5 or 6 feet may be required to serve the largest 
crane ladles. 

Charging. Several feet above the bottom, there is a door in the 
side of the stack, through which the stock is charged into the furnace. 
A platform or scaffold is constructed at a convenient level below 
the charging door, and all stock is charged into the cupola from 
this platform. It should be at least large enough to store the stock 
for the first two charges of fuel and iron. 

Table III, prepared by Dr. Edwin Kirk, gives the approximate 
height and size of charging door and the practical melting capacity 
of cupolas of different diameters. 

Blast. Fan Bloiver. Blast for the cupola is furnished by either 
a fan blower or a pressure blower. Fig. 125 shows a modern fan 
blower, of which the blast wheel is detailed at A. The high speed of 
the blades forces the air, by centrifugal action, away from the 
center of the shaft. The casing is so designed that the blades cut 



FOUNDRY WORK 



113 



TABLE IV 
Fan=Blower Perform 


ance 


Fan Diameter 
(inches) 


Speed 
(revolutions per minute) 


Wind Pressure 
(ounces per square inch) 


18 
24 
36 

48 


4100 
3750 
2900 
2600 


5 
6 

10 
14 



off, as it were, at the top of the main outlet, the air being thus forced 
through the blast pipe. The current of air is continually being drawn 
into the fan through the central opening around the shaft. 

Since air is very elastic, and the pressure in this case depends 
entirely upon the centrifugal action of the blades, should the tuyeres 





Fig. 125, Typical Fan Blower 



become clogged, the amount of air forced into the furnace will be 
reduced proportionately. On the other hand, it requires less power to 
operate the fan with reduced area of outlet than it does when the 
discharge is open free. 

An idea of the speeds at w^hich blowers should run may be 
obtained from Table IV. 

Presstire Blower. In the pressure blower shown in Fig. 126, 
the action is positive, as will be seen from the sectional view A, 



114 



FOUNDRY WORK 



Fig. 126. The wipers mesh into each other in such a way that they 
entrap a quantity of air and force it out of the opening. 

The full quantity of air is therefore forced through the tuyeres at 
all times. In such case, the power necessary to operate the blower 
increases as the tuyeres become choked, and the excessive force of 
the blast, due to choked tuyeres, is hard on the lining of the 
cupola. 

Gage. The cupola should have a blast gage attached to the wind 
box to measure the pressure of air which enters the tuyeres. The 




Fig. 126. Motor-Driven Pressure Blower 



pressure should be sufficient to force the air into the middle of the 
cupola to insure complete combustion. The unit of air pressure is 
1 ounce. From 8 to 16 ounces is approximately the range usual in 
cupolas of from 48 inches to 70 inches diameter, inside lining. 

This pressure is measured by the displacement of water or mer- 
cury in a U-shaped tube. With both legs of the tube the same size, 
as in ^, Fig. 127, the graduations represent the pressure of double 
that height of liquid. Such graduations would be as follows: 



FOUNDRY WORK 



115 



With a water gage, a difference in levels of 1.73 inches corre- 
sponds to 1 ounce wind pressure, so that the scale graduations per 
ounce would be spaced 

1.735 o^rr 55 7 . 1 . 

With mercury, a difference in levels of 0.127 inch corresponds to a 
pressure of 1 ounce so that the scale graduations would be spaced 



0.127 



= .0635 in. 



1 



m. 



V-/0 

9 

— 8 

— 7 

— 6 
5 
4 



— 7 
O 



rp^ 



2 16 

As this last spacing would be too small for practical use, mercury 
gages, as at B, Fig. 127, are made with an increased area exposed to 
the blast pressure, and are graduated 
accordingly. 

Principles of Melting. Combus- 
tion cannot take place without oxy- 
gen, of which the air is the most 
abundant source of supply. For 
example, in the incandescent electric 
light, a strip of carbon is heated to 
a white heat, but it does not consume, 
or burn up, because all air has been 
exhausted from within the globe. 

In the cupola furnace, both coal 
and coke are used as fuel. They con- 
sist largely of carbon, and, after being 
lighted by the kindlings, are kept at 
a glowing red heat by the natural 
draft through the open tuyeres. The 
blast supplies the oxygen necessary 
for a melting heat. The quantity of 
air forced in by the blast cannot be 
entirely taken up by the layers of fuel immediately above the tuyeres; 
thus, complete combustion does not take place until a distance of 
18 to 23 inches above the tuyeres is reached. This is termed the 
melting zone. It is the aim of the melter to keep the top of his bed 
as nearly as possible at this level, so that the iron resting on it shall 
be exposed to this intense heat and melt rapidly. As the fuel of 



B 



/e 

^ /2 
/o 

8 

4 



Fig. 127. Wind Gages 



116 FOUNDRY WORK 

the bed burns away, this level tends to be lowered. But the iron 
on top of it melts and drops to the bottom of the cupola; and 
the subsequent charge of coke restores the level of the bed for the 
next charge of iron; and so on. 

Cupola Operation 

Running a Heat. The following routine must be pursued each 
time a heat is run off in the cupola : 

(1) Clear away the dump from the former heat. 

(2) CM]) out the inside of the furnace with a special hand pick, 
removing the lumps of slag which collect about the lower part of 
the cupola walls, especially above the tuyeres. ^Yhere the slag coating 
is comparatively smooth, do not touch it, as that is the best coating 
possible for the lining. 

(3) Daiib uy with a mixture of fire sand, held together with 
about 1 : 4 fire cla^^, and, wet with clay, wash to a consistency of thick 
mortar. Smear the surface to be repaired with clay wash; then, 
using the hands, plaster the daubing mixture into the broken spots in 
the lining, being careful to rub it in well, especially about the tuyeres. 
The top of the tuyeres should be kept slightly overhanging. 

The greater part of the daubing will be required from the 
bottom to the level of melting zone, about 22 inches above tuyeres. 

(4) Suing uf the bottom doors, and support them by a prop 
of gas pipe. 

(5) Build the bottom; first cover the doors with a 1-inch layer of' 
gangway sand or fine cinders ; then ram in burnt sand tempered about 
the same as for molds. This must be rammed evenly all over the 
bottom, and especially firm around the edges. The bottom should 
be made flat and level from side to side, with only a slight rise around 
the lining which should not extend more than 1 or 2 inches from the 
lining. The pitch varies with size of cupola; 1 inch to the foot will 
answer for cupolas of 24 inches to 30 inches diameter inside lining, 
while one-half that pitch will do for the larger furnaces. 

The cupola bottom should be able to vent so that it will dry out 
quickly, and not cause the metal to boil before the furnace is tapped. 
It should be strong enough to hold its surface during the heat, but 
to break and drop at. once when the bottom is dropped. Too much 
pitch causes excess of pressure on the bott, making trouble in hotting 



FOUNDRY WORK 



117 



Lip; with too little pitch the metal will not drain well, causing 
a tendency to chill at the tap hole. A little daubing mixture 
should be worked into the sand bottom just inside the tap hole, 
to prevent breaking at this point when the tapping bar is forced 
through. 

(6) Lay the fire with shavings first, just inside the breast; 
then with fine kindling; then with enough large kkidling to make 
sure of lighting a layer of coke sufficient to form the bed. When the 
gases from the lower pajt of the bed burn up through, showing that 
the fuel is well lighted, level up the bed with the addition of a little 
more coke. 

(7) The first charge of iron should 
be put on now. Follow this with 
alternate charges of fuel and iron, to 
the level of charging door. 

(8) Forra the tap hole; lay a bar 
of iron about | inch round in the 
spout, projecting in through the breast 
opening; fill in the breast around the 
bar with a strong loamy molding sand 
rammed hard. Recess this in well to 
leave the actual tap hole as short as 
possible. 

(9) Fut on the blast when ready 
for the metal, and leave the tap hole 
open. Bott up when the metal begins 
to run freely — generally about 7 min- 
utes after blast is on. 

Bott clay should be mixed with about \ sawdust, to make it more 
fragile when tapping, and is made up in small balls, and shaped onto 
the end of the bott stick A, Fig. 128. 

(10) Tap when sufficient metal has collected to supply the 
first ladles. 

The tapping bar 5, Fig. 128, has simply a round taper point; 
C is a gouge or spoon-shape, useful for trimming sides of hole if the 
bott does not entirely free itself when tapped. 

(1 1) Drop the bottom, when all the iron has been melted and run 
off. This is done by pulling away the bar that supports the bottom 




Fig. 128. Tapping Bars 



118 



FOUNDRY WORK 

TABLE V 
Foundry=Ladle Data 





Hand Ladle 


Bull Ladle 


Crane Ladle 


Geared Ladle 


Illustration 


Fig. 129 A 


Fig. 129 B, C 


Like C, with 
baU 


Fig. 130 


Control 


Hand shank 


Single or 

double hand 

shank 


Bail with 

single or 

double hand 

shank 


Worm gear 

on heavy 

baU 


Capacity 
(pounds) 


30 
50 


80 
350 


300 
2,000 


1,000 
35,000 


Weight 
(pounds) 


15 
16 


35 
100 


115 
350 


1,900 
7,000 


Dimensions 
(inches) 

Top 
Side 
Bottom 


Inside 
Shell 


Lining 
Thick- 
ness 


Inside 
Shell 


Lining 
Thick- 
ness 


Inside 
Shell 


Lining 
Thick- 
ness 


Inside 
Shell 


Lining | 

Thick-! 

ness 


7 to 8 


! 


9 to 15 


U 


14 to 26 


If 


20 to 75 


2 to 4 


7 to 8 


i 


9 to 15 


Itof 


14 to 26 


f tol 


20 to 60 


ito4i; 


6 to 7 


Hof 


8 to 13 


f to 1 


12 to 23 


lto3 


18 to 66 


IJto 



doors. Throw water on the dump by bucket or hose, to deaden the 
heat, and leave it to cool off over night. 

Foundry Ladles. As the melted metal flows from the spout of 
the cupola, it is caught in ladles. The sizes of these are designated 
by the weight of metal they will hold; they vary from 30 pounds 
to 20 tons capacity. 

Table V, containing references to Figs. 129 and 130, give compact 
data regarding foundry ladles. 

The names of ladles relate to the method of carrying them. 
Hand ladles are made of cast iron or pressed steel. The larger 
ladles are built up of boiler plate. Cast iron is poured from the top 
of the ladle, which should therefore be provided with lips. 

Lining, Ladles must be lined to protect them from burning 
through. Up to 1-ton capacity, the cupola daubing mixture is used. 
The bowl is smeared with thick clay wash, and the clay pressed in 
hard with the hands, being rubbed smooth on the inside. The 
lining should be kept as thin as possible, f to f inch on hand ladles, 
1 inch to 1| inches on large ones; the bottom lining being from 



FOUNDRY WORK 119 

one-third to one-half thicker than sides, as it receives the first fall 
of the incoming metal. 

The larger ladles are first lined with fire brick of thickness pro- 
portionate to their size, and then daubed on the inside with clay 
mixture similar to cupola lining. The lining must be well dried before 
use, to drive out moisture. In stove-plate and hardware shops, 
where most of the pouring is done with hand ladles, a special ladle 
drying stove similar to a shallow core oven is provided. A wood fire 
is built inside of the larger ladles to dry them out. To preserve a 
lining as long as possible, slight breaks are repaired daily. As with 
the cupola, the slag formed by the hot metal forms the best coating 
possible for the inside lining. 

Pouring, The first thing to be considered in connection with 
pouring is skimming off the slag which collects on top of the metal. 
This should be done on 
the larger ladles before 
leaving cupola, and again 
while metal is being 
poured. For this, a long 
iron rod is used, with 
blade shaped as in D, ,...<.« t. ,, ^ „x „ 

^ ' Fig. 129. Hand and Bull Ladles 

Fig. 128. This is rested 

across the top of the ladle near the lip, and effectively holds the 
slag back; the long handle permits the skimmer to stand well back 
from the heat of the metal. On small ladles, skimmers are of course 
shorter, and the end is bent up more, for convenience, as the ladles 
will be much nearer the floor when pouring with them. 

Hand and bull ladles are shown in Fig. 129, while Fig. 130 shows 
a crane ladle. 

General Precautions. Much skill is required in pouring a mold. 
A molder must know the character of the work, and judge whether 
it must be poured fast or slowly. In general, light work cannot 
be poured too fast. Heavier work is poured more slowly. Care 
must be exercised to keep the stream steady from the first, and not 
to spill into the mold, as this may cause cold-shuts or leave shot iron 
in the castings. The runner basin must be kept full, for gates and 
runners are made with this express purpose in view, as has been stated 
previously. 




120 



FOUNDRY WORK 



INIetal must not be allowed to chill or freeze in the ladle, as this 
would destroy the lining when it came to removing the cold metal. 
Metal left in the ladles when the mold is full, must be poured back 
into a larger ladle or emptied into a convenient pig bed. These latter 
are built in a sand bed usually near the cupola; or stout cast-iron pig 
troughs or chills are provided. The chills should taper well on the 
inside, holding about 60 pounds each. Some are arranged to swing 
on trunnions for convenience in dumping. They should be smeared 
with a heavy oil and dusted with graphite, to prevent the metal stick- 




Fig. 130. Crane Ladle 

ing in them. It is safer to heat these pig molds as well, so that no 
moisture will form and cause a kick or explosion when hot metal is 
first poured into them. 

Cupola Mixtures 

Requirements, By the term cupola mixture is meant the propor- 
tioning of the various pig irons and the scrap that make up cupola 
charges, with the object of obtaining definite physical and chemical 
properties in the resulting castings. 

The requirements of castings vary; and metal that would be good 
if run into thin stove plate, would be entirely too soft for heavy 
machine castings. Again, iron that might answer all requirements of 
a bed plate would not be strong and tough enough for steam-cylinder 



FOUNDRY WORK 121 

work. The one in charge of this work, therefore, must so mix the 
different irons that his castings shall be soft enough to machine well if 
necessary, and at the same time be hard enough to stand the wear and 
tear of use. 

Precision Essential. Formerly the appearance of the fracture of 
a pig or of scrap was the sole guide in determining mixtures. Unques- 
tionably the fracture of iron indicates to the experienced eye much 
as to its physical properties, but this method of mixing has repeatedly 
proved misleading. 

Representative practice today recognizes chemical analysis of 
the various irons as most essential to the proper mixing. Many firms 
now buy their pig iron and many other allied supplies by specification; 
and the chemical analysis of the iron must show that its various 
metalloids come within certain limited per cents. 

To understand, then, these modern methods, we must consider 
the subject of the chemistry of iron. 

Affecting Elements. By the chemical definition, an element 
is a form of matter which cannot be decomposed, or, in other words, 
cannot be broken up into other forms by any means known to science. 

Iron is such an element; but absolutely pure iron is of no com- 
mercial value; it is only when it is combined with impurities — or, as 
we must recognize them, other chemical elements — that mankind is 
interested in it. 

In the forms of iron with which we are dealing — pig iron, and 
cast iron — five elements are considered as affecting their physical 
properties. These elements are carbon, silicon, sulphur, phosphorus, 
and manganese. 

Carbon. Carbon is the most important and most abundant of 
all the chemical elements. It forms the principal part of many 
substances in daily use about us, such as coal, coke, lead pencils, 
graphite facings, etc. 

In its relation to iron, carbon is peculiar in that it occurs in iron 
in two forms. One is in a chemical combination forming a hard 
substance with a fine grain, of which tool steel is the purest type. The 
other is simply a mechanical mixture forming minute facets of free 
carbon interposed between the crystals of the combined form. It 
softens cast iron, but weakens it by causing larger crystals to form. 
In drawing the finger across a freshly cut surface or fracture of cast 



122 FOUNDRY WORK 

iron, some of this free carbon may be rubbed off, and shows as dirt 
on the finger. We shall use the term graphite in referring to this form 
of free carbon, and the term combined carbon in referring to the element 
in its combined state. 

Silicon. Silicon, of itself, is a hardening element in cast iron, 
but on account of its marked influence upon carbon formations, it is 
usually considered a softener. During the cooling process, silicon 
retards the formation of combined carbon, thus increasing the forma- 
tion of graphite in proportion to the increase of silicon. At the same 
time, through its own influence on iron, it preserves the fine 
character of the grain, and so maintains the strength of the cast- 
ing. In other words, within certain limits, the addition of silicon 
softens castings without impairing their strength. It makes iron 
run more fluid, and reduces shrinkage. Silicon varies in castings 
from 1.50 to 2.50 per cent. 

Sulphur. Sulphur is the most injurious element in iron. It 
makes castings hard, red-short, and tends to the formation of blow- 
holes. At the melting temperature, iron absorbs sulphur from the 
fuel — a decided reason why foundry coke should be as free as possible 
from this element. Sulphur in castings should not exceed 0.07 
per cent. 

Phosphorus. Phosphorus tends to make iron run very fluid 
when melted. It is a hardener. For machine castings it should not 
exceed 1 per cent. 

Manganese. Manganese strengthens, and, of itself, hardens 
iron. Chemists are beginning to consider its proportions more care- 
fully, in the behef that under certain conditions it acts as does silicon, 
softening the castings while retaining their strength. It is usual to 
keep it below 0.50 per cent. 

Factors of Quality. The strength of a casting and the finish 
which it is capable of taking are largely dependent upon its having a 
fine even grain. We have seen that the porportions between the com- 
bined carbon, the graphite, and the silicon have decided influence 
upon this condition. But the rate of cooling must also be taken into 
account. A thin casting cools rapidly, tends to increase the combined 
carbon, and, without the influence of silicon, would be hard and 
brittle. In a heavy casting, the metal stays liquid longer, more 
graphite is thrown off, and the casting is naturally softer. There- 



FOUNDRY WORK 



123 



fore light work requires a larger proportion of silicon to counteract 
the effect of the rapid cooling than does larger work. 

Chemical Analysis. Modern practice makes daily analysis for 
the two carbons, for the silicon, and the sulphur, occasionally testing 
for the other elements to see that they are kept within their safe 
limits. Silicon, however, is used as the guide for regulating mixtures. 

Proportions of Silicon, The following shows good proportions 
of silicon for different classes of work : 



Casting 



Steam cylinders 

Medium heavy work (|-inch to 2-inch thickness) 

Light work (less than ^-inch thickness) 



Silicon 
(per cent) 



1.70 
2.00 
2.50 



A more complete analysis of results to be aimed for is: 



Casting 


Elements 
(per cent) 


[.Silicon 


Phosphorus 


Sulphur 


Manganese 


Automobile cylinders 
Corliss engine cylinders (Ij- to 
l-2--inch thickness) 


2.25 
1.20 to 1.70 


1.0 

below 0.1 


0.075 
below 0.095 


0.5 
0.5 



To calculate for any result, we must first know the analysis of the 
irons to be used in making the charge. We shall consider silicon as 
the guide. 

In keeping track of results, the proportion of silicon in the 
local scrap of an establishment can be accurately estimated. With 
miscellaneous machinery scrap, this is more difficult; the following, 
however, are safe estimates: 



Casting 


Silicon 
(per cent) 


Small thin scrap 
Large scrap ranges 


2.0 to2.4 
1 . 50 to 2 . 



Method. The analysis of pig iron is made from drillings taken 
from a fresh fracture. Between the very fine grain about the chilled 
sides of the pig and the very coarse grain in the center, average-sized 



124 



FOUNDRY WORK 



crystals will be noticed in the fracture. It is here that the drillings 
for analysis should be made, as indicated in Fig. 131. About a 
J-inch flat drill is best to use, as it cuts a more uniform chip from the 
varying grades of pig than does a twist drill. 

To determine the analysis of a carload lot of pig iron, the 
following method is employed : Select ten pigs which will represent 
an average of the close, medium, and coarse-grained iron in the car. 
These pigs should be broken, and drillings taken from the fresh 
fracture. The drillings from these ten fractures are thoroughly 

mixed together, and about 2 ounces by 
weight, or a large tablespoonf ul by meas- 
ure, is sufficient for the chemical analysis. 
The result is taken as the average analysis 
of the carload. 

The smaller foundries who do not 
employ a chemist can get a good work- 
ing analysis of their iron from the fur- 
nace from which it is bought. Or, in 
many cases, sample drillings are sent to a practicing chemist. 
Usual Silicon and Sulphur. The proportions of silicon and 
sulphur contained in the ordinary grades of pig iron are approximately 
as follows : 




Fig. 131. Section of Pig Drilled 
for Analysis 



Grade of Pig 


Silicon 
(per cent) 


Sulphur 
(per cent) 


Ferrosilicon 
Silvery 

No. 1 foundry 
No. 2 foundry 
No. 3 foundry 


7 to 12 
3 to 5 
2.50 to 2.90 
1.95 to 2.40 
1.40 to 1.90 


0.03 
0.03 
0.03 
0.04 
0.05 



Calculation of Mixture. When we have the analysis of our iron, 
we can proceed to calculate the mixture, bearing in mind that some 
of the silicon will be burned out of the iron during the heat. From 
0.15 to 0.25 per cent is a fair estimate for this loss in cupolas ranging 
in size from 3G inches to 72 inches inside lining. This loss must be 
deducted from the final estimate. 

Illustrative Examples. It is proposed to make a mixture for 
miscellaneous machinery castings which require about 2 per cent 



FOUNDRY WORK 



125 



of silicon, and we wish to use one-half scrap and three other irons, 
whose silicon contents are as follows: 



G RADIO OF Ikon 


SlI-lCON 
(per cent) 


Silvery 

No. 1 foundry 
No. 2 foundry 
No. 3 foundry 
Scrap 


4 

2.6.5 

2.22 

1.75 

2.00 



The student should bear in mind that per cent means t4() 
or .01. To multiply a whole number by per cent, set the decimal 
point two places to the left in the percentage; thus 35 per cent of 
5,000 = .35X5,000 = 1,750. In multiplying per cent by per cent, 
set decimal points in the percentages one place to the left before 
multiplying, and the result is expressed as per cent; thus 25% of 
35% = 2.5X3.5 = 8.75 per cent. 

Then we may have the following proportions of silicon, using the 
above irons: 

(A) . (B) (C) (D) 

No. 1 25%X2.65% =0.6025% 

No. 2 20% X2.22% =0.4440% 

No. 3 5% X 1.75% =0.0875% 

Scrap 50% X2.00% = 1.0000% 



= 2.194 ^ 
= 0.20 9 



Total silicon content 
Deduct for loss in heat 

Estimated silicon in result =1.994 % 

Or, with No. 2 and silvery irons, we may have: 

(A) (B) (C) (D) 

No. 2 45% X2.22% =0.999 % 

Silvery 5%X4.00%)=0.200 % 

Scrap 50% X2.00% = 1.000 % 

Total silicon content =2.199 % 

Deduct for loss in heat =0.17 % 

Estimated silicon in result =2.029 % 

In these examples, column {A) is the kind of iron; (B), per 
cent of this iron used in charge; (C), per cent of silicon in single 
grade of iron; (D), per cent of silicon to whole charge as supplied 
by each grade. One or more per cents in column {B) are usually 



126 



FOUNDRY WORK 



decided upon before beginning calculations, and then the others are 
varied until the desired silicon content is obtained. 

With this as a guide, it is a simple matter to find the actual weight 
for each grade, to make up any size of charge. For example, we wish 
to put 5,000 pounds on the bed and 3,000 pounds on other charges. 
Then, using the first mixture and the ratio 5 : 3 between the bed and 
the other charges, we have : 

From column (B) Bed Other charges 
No. 1 25%X5,000 = l,250 1b. 7501b. 
No. 2 20% X 5,000 = 1,000 lb. 600 lb. 
No. 3 5%X5,000= 2501b. 1501b. 

Scrap 50% X 5,000 = 2,500 lb. 1,5001b. 



Total iron 



5,000 lb. 3,000 lb. 



Fuel. Both anthracite coal and foundry coke are used in the 
cupola. Coal, owing to its density, carries a heavier load than coke, 
but it requires greater blast pressure and does not melt as fast 
as coke. 

Foundry Coke. Coke, for foundry use, should be what is known 
as "72-hour" coke, as free as possible from dust and cinders. Coke is 
made up of a sponge-like coke structure which is almost pure fixed 
carbon, and an open cellular structure, which makes it especially 
valuable as a furnace fuel because it is so readily penetrated by 
the blast. 

A representative analysis of a strong 72-hour coke is as follows: 



Item 


Proportion 
(per cent) 


Moisture 
Volatile matter 
Fixed carbon 
Sulphur 
Ash 


0.49 
1.31 

87.46 
0.72 

10.02 


Cellular structure 
Coke structure 


50.04 
49.96 


Heat units per pound 


12,937 B.t.u. 


Specific gravity 


1.89 



Proportions of Charge. The proportions of the bed fuel, the 
first charge of iron, and the subsequent charges of fuel and iron vary 



FOUNDRY WORK 127 

greatly with the size and design of the cupola, the grade of fuel used, 
and the method of charging. To determine the right amount of fuel 
for the bed, the most practical thing to do is to cut and try, especially 
with a new equipment. 

For 36- to 48-inch cupolas, averaging 22 inches above the tuyeres 
for the melting zone, with a 10-ounce blast to start, the best way to 
proceed is to chalk off this distance inside the cupola before daubing 
up. Then, from a J-inch rod of iron, bend a shape like Fig. 132. 
The distance a equals the distance from the mark inside the cupola 
to about 4 inches above the bottom of the charging door. When the 
coke is well lighted, before charging the iron, level off the bed accord- 
ing to this gage. The safe practice is to have the bed too high. If the 
bed is too high, it is indicated by slow but hot metal; if the bed 
is too low, the metal is dull. After 
the first heat, the height may be 
adjusted until proper melting is 
obtained; then try always to work 
to the same height. 

The weight and character of the 
coke charged on the bed should be 
carefully noted. The first charge of metal should be in the pro- 
portions of 2 pounds of metal to 1 of fuel ; all others in the ratio of 
10 of metal to 1 of fuel. Intermediate charges of coke should be 
just sufficient to preserve the upper level of the bed. The layer is 
usually about 6 inches thick; its weight should be carefully taken. 

The action of the furnace must be carefully watched, with the 

object of making it melt the iron charged as rapidly as possible and 

of bringing it down white hot. Also, the ratio of iron to fuel should 

be reduced as low as may be, without sacrificing either of these other 

objects. 

Supplementary Operations 

Sand Mixing. When a mold is poured, the intense heat of the 
iron burns out those properties in the sand which give it its bond, 
making it necessary that a certain proportion of new sand shall 
be mixed with the heap sand and used as facing, as has been explained 
in earlier paragraphs. 

The facing sand should be mixed daily for the molders by one 
or more of the laborers, at a place convenient to the storage sheds 



Fig. 132. Bed Gage 



128 



FOUNDRY WORK 



and molding floors. A hard smooth floor of clay or of iron plates 
is a great advantage. 

The proportions of the different sands are measured by the 
shovelful, bucketful, or barrowful, and the sands are spread over each 
other in flat layers, sufficient water being sprinkled on to temper the 
pile. The sand then is cut through once with the shovel, is put through 
a No. 2 sieve, all lumps being broken up, and the refuse thrown 




Fig. 133. Rotary Sieve 

out is put through a No. 4 sieve, and finally is thrown in a pile 
ready for use. , 

When this work is done by hand, the ordinary screen sieve com- 
monly employed by masons is used for the riddling, and a round 
foundry riddle for the final sifting. To reduce the labor of this, the 
riddle is slid back and forth on a pair of parallel bars supported 
conveniently above the storage pile. 

Mixing Machines. The two classes of labor-saving machines 
used in mixing facings, core sand, etc., are those which mix by 



FOUNDRY WORK 



129 



riddling; and those which mix by a combined breaking and stirring 
action. There are many varieties on the market, the illustrations 
shown being typical. 

The rotary sieve shown in Fig. 133 is made with wire screen on 
the revolving sides, and is driven by belt or connected motor. Sand 
shoveled into the central 
opening is sifted in a pile 
on the floor, or directly 
into a barrow. The rub- 
ber hammer on top auto- 
matically raps each face 
of the sieve as it re- 
volves, knocking the 
meshes free of sand. 

Fig. 134 shows one 
of the latest labor savers Pi^ i34 ^^^^ ^^^^^^ 

in this line. Here a 

foundry riddle is supported in a metal ring attached to the piston 
of the machine. It is made to vibrate rapidly by means of com- 





Fig. 135. Pulley-Driven Centrifugal Mixer 



pressed air or steam. These shakers are made with portable tripod, 
as shown; they are also made stationary or are fastened on a post 



130 



FOUNDRY WORK 



by means of a swivel joint, to be swung over a wheelbarrow or over 
a molding machine, and out of the way again when not in use. 

Fig. 135 shows a centrifugal mixer. Inside of the umbrella 
casing, a horizontal plate about 12 inches in diameter and carrying 
a number of vertical steel pins about 6 inches long is fastened to the 
top of a short upright shaft driven by a belt running inside of the 
casing shown at the base of the machine. The machine runs about 
1,500 revolutions per minute; and sand shoveled into the hopper is 
very evenly broken up by the pins and thrown against the steel hood, 
breaking and shattering any lumps of clay or loam and making a 




Fig. 136. Facing Grinder 



very uniform mixture. The hopper may easily be removed to clean 
the plate. The machine is used for the final mixing. 

Fig. 136 shows a foundry grinder or facing mill. It is the type 
of mill used for mixing loam. Either the pan or the rollers are 
attached to the driving shaft and made to revolve, crushing and 
mixing whatever is shoveled into the pan. Frequently, a stout blade, 
something like a plowshare, is fixed between the rollers, and prevents 
the mixture caking to the bottom of the pan. The faces of "the rolls 
are of very hard or of chilled cast iron to withstand wear. When the 
loam mixture is sufficiently ground, it must be shoveled from the pan, 



FOUNDRY WORK 131 

and delivered to the molders or stored temporarily. It will set if 
stored too long. This is the type of mill used in the steel foundries, 
for grinding the facing materials. The various sands are dumped 
into the pan at one side, and, when ground sufficiently, are shoveled 
directly from the pan into a centrifugal mixer. This prepares them 
for use. 

Cleaning Castings. After a casting has solidified in the mold, 
the flash should be removed, leaving the casting in the sand. For 
light bench work and snap-flask work, the mold is lifted bodily and 
the sand dumped on the pile; the bottom boards are piled in one 
place, and the cases are piled in another ready for the next day's 
work. As the molds are dumped, the castings are removed from the 
sand and piled at the edge 
of the gangway. When ail 
castings have been removed 
from the sand, the gates 
are broken and thrown in a 
pile by themselves. W^hen 
cold enough to handle, the 
castings are removed to the 
cleaning room, and the gates 
and sprues are sent to the 
scrap pile. With heavier 

n Till Fig. 137. Dustless Tumbling Barrel 

noor work, the clamps are 

removed as soon as the casting has set; the flash is rapped with a sledge 
hammer and is stripped off the mold, leaving the castings to cool 
gradually in the sand. Sometimes a sharp blow is given on top of the 
runner while it is still red; this breaks it off before the flask is shaken 
out. At a red heat, cast iron is very weak and can easily be broken. 
Tumbling. The most effective way to clean small castings is in 
a rattling barrel. Fig. 137 shows a modern set of dustless barrels. 
The shell of the barrel is f-inch boiler plate riveted to cast-iron 
heads, with a door arranged to be entirely removed for packing and 
dumping. The bearings are hollow, and from one end the dust is 
drawn off through a galvanized-iron pipe. This pipe connects with 
an air-tight wooden chamber, as shown in Fig. 138, varying in size 
with the number of barrels connected with it. In this chamber hang 
a number of cloth-covered screens. An exhaust fan is connected to 




132 



FOUNDRY WORK 



this chamber at the opposite end from the inlet pipe. When the fan 
is in operation, a strong current of air is drawn through the barrels 
and through the chamber. The dust, entering the chamber, settles 
on the screens, so that but little dust escapes to the outside air. 
When necessary, the exhaust is stopped, and, by means of a crank 
on the outside of the dust chamber, the screens are shaken and 
the dust drops off, when it can be removed through a trap into an 

ash can or wheelbarrow. 
The driving shaft 
carrymg the pinion re- 
volves all the time, and 
any barrel may be thrown 
over into gear or drawn 
out of gear by the opera- 
tion of a hand lever. The 
barrels should run about 
25 revolutions per minute. 
Each barrel should be 
packed as full as possible 
with several shovelfuls of 
gates, shot iron, or hard- 
ened stars thrown in with 
the castings. The clean- 
ing is accomplished in 
from 20 minutes to half 
an hour by the scouring 
action of castings, scrap, 
etc., rubbing against each 
other. Castings up to 50 or 100 pounds can be rattled, but only 
those of a similar character as to design or weight should be packed 
in together, otherwise the lighter castings will be broken by the 
heavier. When removed from the barrel, the work should show a 
smooth clean surface of an even gray color. 

From the rattlers, castings go to the grinding room, where pro- 
jecting gates or other slight roughness is removed on the emery 
w^heel. 

Heavy castings are cleaned by hand, by pickling, or by sand- 
blasting. 




Fig. 138. Dust Collector for Tumbling Barrel 



FOUNDRY WORK 



133 




Fig. 139. Steel Bristle Brush 



Hand-Cleaning. When cleaning by hand, the worst of the sand 
is rapped off by light hammering, the remainder scraped off with 
old files and with steel-wire brushes such as that shown in Fig. 139. 
Some shops rub off finally with broken 
pieces of coarse emery wheel. Risers 
and fins are removed with cold chisels. 
The pneumatic chisel, shown in 
Fig. 140, is used as a timesaver. 
Where work is light enough to handle, 
small fins are .removed by emery 
wheels; medium coarse wheels will 
cut faster on cast iron than fine ones, 
and will hold their shape better. 

It is when castings must be 
cleaned by hand, that the value of a good facing dust shows itself. 
With the proper facing, the sand parts readily from the casting 
leaving a fine-looking smooth surface. With poor facings, on the 
other hand, the iron burns 
into the sand, making it 
hard to clean, and leaves 
a rough surface on the 
work. 

Pickling. Pickling is 
a method of cleaning re- 
sorted to where there is 
much machining to be done 
on a casting. The work is 
placed in a pile on a suit- 
able platform, and dilute 
sulphuric acid is thrown 
over it during one day, 
frequently enough to keep 
it well wet. The platform 
should be arranged to drain 
the acid back into the vat. Acid is diluted from 1 : 8 to 1 : 10. After 
about 12 hours' bath with acid, the castings are washed clean with hot 
water. The acid acts on the hard skin of oxide of iron which forms 
when the iron strikes the damp sand, and it eats through this skin to 




Fig. 140. Pneumatic Chisel for Cutting 
Risers and Fins 



134 FOUNDRY WORK 

the iron itself. The washing water should be hot enough to warm 
the castings sufficiently for them to dry rapidly without rusting. 
The acid must be thoroughly washed off, or it will continue to eat 



Fig. 141. Sand-Blast Arrangement 



into the iron and cause a white powder— sulphate of iron — to form 
on the surface. 

An excellent arrangement for a pickling department is to have 
the trough arranged on skids which allow it to be rocked endwise. 



FOUNDRY WORK 



135 



This drains into the pickling vat when acid is being thrown on, and 
into the gutter when the castings are being washed. Sheet lead is the 
best protective covering for small pickling troughs, but it is expensive 
and not durable enough to stand for heavy work. 

Sand-Blasting, For castings of such shape and size that they 
cannot well be rattled, but are too small to be cleaned by hand, the 
sand blast has been used to advantage in many shops. 

Fig. 141 gives an idea of the arrangement of the cleaning stall. 
Castings are placed on the wooden grating. By means of com- 




Fig, 142. Core Rod Straightener 

pressed air a sharp silica sand is forced through a strong rubber hose 
and is directed against the castings by a hardened-steel nozzle. 
The operator wears a helmet supplied with fresh air by an air hose, 
to protect his eyes and lungs from the clouds of fine dust. An exhaust 
hood is arranged also to take off as much of the dust as possible. 

The manual labor of this method is practically reduced to noth- 
ing, aside from handling the castings. The system, however, requires 
the installation of a rather considerable equipment, which has debarred 
its use in many foundries. 



136 FOUNDRY WORK 

Re-Use of Core Rods. In removing cores, the bars become very 
much bent. In such shape they were formerly scrapped, or refitted 
to suit new cores with a hammer and block of iron. Fig. 142 shows a 
very practical power machine which delivers the bars perfectly 
straight. The machine consists of a pair of rolls, with different 
sizes of grooves turned in them, which pull a rod through a flaring 
mouthpiece and deliver it through a corresponding eye on the 
opposite side. The machines are made in different sizes, and take 
rods from i-inch to f -inch diameter. 

STEEL WORK 

Present Development. This class of work has developed within 
the last few years, and, beginning with the heavier parts of marine 
and engine construction, it is now crowding the field of drop forgings. 
Steel castings are malleable, and are very much stronger than iron 
ones. The principles of molding involved are similar to those in 
other classes of molding, but practice is varied to meet special 
conditions. 

Processes, The art of making steel castings may be divided 
into three heads: (1) preparation arid melting of the metal; (2) 
making and pouring the molds; (3) heat-treatment of finished castings. 
As the first and third heads come more properly under other depart- 
ments, we shall here simply outline these processes, dealing in detail 
with the second heading only. 

Characteristics of Metal. This branch of foundry work has 

developed to a great extent since the early nineties. The metal is 

similar in mixture, method of melting, and physical properties to the 

steel which is poured into ingot molds for forging purposes. The 

graphitic carbon is entirely burned out; the strength of the metal is 

therefore very much greater than that of cast iron. Combined carbon, 

manganese, and silicon are the elements depended upon for this 

strength; sulphur and phosphorus are kept very low. A typical 

analysis shows these elements in the following proportions : 

Carbon Manganese Silicon Sulphur Phosphorus 
0.27% 0.85% 0.35% 0.020% 0.025% 

Owing to the purity of this form of iron, about 50 per cent more 

heat is required to melt it than is necessary in the case of pig iron — 

or about 3,300 degrees Fahrenheit. When melted, the metal runs 



FOUNDRY WORK 



137 



much more sluggishly than cast iron, and, on account of the absence 
of graphitic carbon, it does not expand at the moment of solidifying, 
and therefore does not take as sharp an impression. To insure as 
perfect an iilipression as possible, the molds are constructed with a 
good head of metal in the risers, and they are poured under pressure. 
The shrinkage is double that of iron; the risers are made very large, 
and are placed directly on the casting to insure feeding well. Great 
care must be exercised 
that neither mold faces 
nor cores bind during 
cooling, as such binding 
might cause a flaw. 

Shrinkage, When 
two surfaces meet at right 
angles, the corner re- 
mains hot longest, and 

the sides shrink away, tending to cause a fracture at a, Fig. 143. 
To overcome this, thin webs are cut by the molder about every 
4 inches or 6 inches — shown at b. These cool first, and hold the 
adjacent sides in position, preventing them from pulling away from 
each other. The internal strain due to this cooling is relieved by the 
annealing. After the casting is annealed, the webs are cut away. 




Fig. 143. Shrinkage Webs 



STEEL MOLDS 

Facing Mixtures. To withstand the high heat, pure silica sand 
is used as the basis of the facing mixtures for steel molds. Pure 
quartz or silica rock is quarried, and reduced to sand form through 
a series of rock crushers. At the foundry the necessary bond is given 
by the addition of fire clay and molasses water. These are thor- 
oughly mixed with the sand in a facing mill and mixer, Figs. 135 and 
136. A typical mixture is as follows : 

1 barrow silica sand 

3 pails powdered fire clay 

Temper with molasses water 

Where quartz sand is very expensive, the following mixtures, 
I, II, III, or IV, will reduce the cost. The old crucibles and fire brick 
should be crushed separately in the mill before mixing. 



138 



FOUNDRY WORK 



Ingredients 


Proportions 


(Castings up to 2 In. 
Thick) 


(Castings over 2 In. 
Thick) 


(I) 


(II) 


(HI) 


(IV) 


Old facing sand 
Old crucibles 
Fire brick 
Fire clay 
Coke 

Silica sand 
Graphite 


8 
2 
2 
2 
1 


12 

1 

5 
2 


1 

10 
5 
3 
1 


1 
5 


Tempering medium, molasses water 



Yor facing ivash, these mixtures are ground very fine, and thinned 
with molasses water. 

Core sand for steel work is practically the same mixture as the 
mold facing. For thin metal a somewhat less refractory natural 
sand may be added to reduce the cost of the mixture. 

For S7nall round or flat cores, -gV part rosin, with silica sand, 
tempered with molasses water, makes a good core. It should, 

however, be thoroughly 
burnt. 

For core-icash mix- 
ture, use 3 parts silica 
flour; 1 part Ceylon 
graphite; molasses 
water. 

Flasks. Flasks for 
steel work are built of 
cast iron. Fig. 4, Part I. 
Full-length crossbars are 
bolted in the cope, 6 
inches to 8 inches on centers, depending on the size of the flask. 
Short crossbars are fastened between these as needed, say 12 inches to 
16 inches on centers, as seen in Fig. 144. Oblong bolt holes 4 inches 
on centers are cast in the sides of the flask and in all crossbars. 
Slots to correspond are cast in flanges of bars, so that they may be 
readily removed or shifted when fitting the cope to the pattern. 




Fig. 144. Short Crossbar 



FOUNDRY WORK 



139 



The holes for pins should be drilled to template in all flasks of the 
same size, so that copes and drags may be interchanged. Flask pins 
are slipped through the holes temporarily when the flask is being 
closed or opened. 

On large work the cope is bolted to the drag while being rammed. 
The bottom plate is of cast iron, and is clamped to the flange of the 
drag with short clamps and steel wedges. The same tools are used 
for packing and finishing the mold as those described in connection 
with iron molding. 

Flasks of from 18 inches to 48 inches in length have two handles 
bolted on the ends to lift them with. Larger flasks have trunnions, 
rockers, or U-shaped handles cast on the sides. 




Fig. 145. Small Flask for Steel Molds 

Fig. 145 shows type of convenient small flask built up of channel 
and angle iron, size 14 by 20 to 24 by 48 inches. 

Packing. In packing the mold, place the pattern on the board 
and cover with 1| to 3 inches of facing, depending on the size of the 
job. Tuck well with the fingers. The facing is used as prepared by 
the mixer, not sifted. Set the drag on the board, shovel in heap sand, 
and ram the mold somewhat harder than for iron. Strike off, and 
seat the bottom plate, fastening it firmly to the flange of drag with 
clamps or bolts. When this is done, roll the mold over, and remove 
the moldboard. 

Press with the fingers all over the joint surface, especially 
around the pattern, to make sure of firm packing. If soft places are 



140 



FOUNDRY WORK 



found, they should be tucked in with facing sand. When needed 
repairs are made, slick the joint all over. Use burnt core sand for 
making the parting. 

Try on the cope and adjust bars to fit the pattern. Clay-wash 
the cope before packing. Put on necessary facing over the joint 
and the pattern. Set the gate on the joint, but place risers directly 
on the pattern. Set the necessary gaggers, shovel in heap sand, and 




-vy//;y/;vy//yy//yyyy^^^ 



Fig, 146. Section Through Steel Mold 



ram the cope. Vent well, lift the cope, moisten the edges, and 
draw the pattern. 

In finishing the mold, nails are used freely, about 1| to 2 inches 
apart, driven in till the heads are flush with the surface of the sand. 
This is to prevent the cutting of the surface by the rush of hot metal 
when the mold is poured. 

It is at this stage that the thin webs previously mentioned, are 
cut into the corner fillets where needed. The whole surface of the 
mold must be smoothly slicked over with the trowel and convenient 
slicks. When this is done, paint on the facing wash with a very 
flexible long-bristled brush. 



FOUNDRY WORK 14i 

Fig. 146 shows the section of a mold for a shrouded pinion, and 
illustrates the points above mentioned. The runner is lead in at the 
bottom by use of a cover core, as described in Dry-Sand Molding. 

Molds for steel should be more than dried; they should be 
thoroughly baked to drive off every particle of moisture. This 
prevents the steel boiling in the mold and causing imperfections in 
the casting. 

• Where but little machine work is to be done on small work up to 
IJ inches thick, the molds may be made up in wooden flasks and 
poured green. For this class of work, only pure quartz sand and 
fire clay are used, tempered with molasses water. These may be 
made up and poured on the same day. 

Cores. Cores for steel molds are made up in boxes similar to 
those used in the iron foundry. Although using special sands, the 
cores are strengthened w^itb iron rods, vented with cinders, and 
provided with convenient hangers for lifting, as described in previous 
paragraphs. 

Where cores must be made in halves, one set of half-cores may 
be made and baked. The other half is then made and rolled over 
directly on the baked half. Fire-clay wash is used to cement the 
joint. This method allows the joint between the halves of a core to 
be nicely slicked down. 

Steel cores must be more collapsible than those for iron, on 
account of the excessive shrinkage of the metal. This is provided 
for in the mixture of the sand used, and by thoroughly baking the 
core to reduce the effect of the binding materials to a minimum. 

STEEL CASTINGS 

Running a Heat. Open- Hearth Melting, The melting of steel 
is a science by itself, and cannot be dealt with adequately in an 
article of this character. Only a very brief description of the 
process is given. 

The main feature is the difference in application of heat. Metal 
is melted in what is termed the open-hearth furnace, a sectional plan 
of which is shown in Fig. 147. The charge of scrap steel and pig iron 
is placed on the central hearth. Heat is obtained by producer gas 
supplied with air blast. Both gas and air are heated in one set of 
regenerators before entering the combustion chamber. The flame 



142 



FOUNDRY WORK 



plays on top of the charge, and the waste gases pass off through 
the other regenerator section of the furnace, heating up its brick- 
work. The direction of the gases is changed about every 20 minutes. 
The regenerator is practically a tunnel about 15 feet long, filled with 
brickwork built up as shown in Fig. 148. About 4 heats a day are 
run from the furnaces. 

Samples of the bath are analyzed at intervals during the heat. 
Guided by these analyses the proper proportions of ores, fluxes, 




Region orators 



Reg en era tors 



Fig. 147. Section through Open-Hearth Furnace with Regenerators 



and pig are added to the bath to give it the right composition, a 
typical analysis of which has been given. 

Pouring, When the bath is in proper condition, the entire charge, 
be it 5 tons or 40 tons, is drawn off into a ladle previously heated by 
a special gas burner. This ladle is lifted by the crane and carried to 
the pouring floor. 

In order to secure the soundest metal free from pent gases or 
slag, all steel for casting purposes is tapped from the bottom of the 
ladle. The stopper is carried by a stiff round bar encased in fire-clay 
tubing. This passes through the liquid metal, as in Fig. 149, and may 
be raised or lowered by an arm attached to a rack-and-pinion mech- 
anism bolted to the outer shell of the ladle and operated by means of 
a large hand wheel. The ladle is swung into position with the tap 



FOUNDRY WORK 



143 



hole directly over the pouring head. Four men hold the ladle steady 
with long iron rods. The metal thus enters the mold under the head 
of pressure of all the steel above 



Fig. 148. 



I CT 



U C4 



How Brick Is Set in Regenerators 



it in the ladle. 

When all the steel is drawn 
from the ladle, the latter is swung 
on its side near the furnaces, the 
stopper is removed, and all the 
slag possible is racked out. The 
ladles must be repaired after each 
heat, often to the extent of replac- 
ing one-half of the thin fire-brick 
lining. The casing of the 
stopper will last for but one 
heat, as the rod is sure to 
get bent out of shape. The 
rods are repaired by a black- 
smith before recasing them. 

Setting Up Molds. Set- 
ting up is usually done by 
a different set of men from 
those employed to make the 
molds. 

For convenience in pour- 
ing, runner boxes, such as 
shown in Fig. 150, and which 
serve simply as funnel-shaped 
mouths to the runners, are rammed up 
in small round sheet-metal boxes, using 
a wooden pattern to form the hole. 
These are baked in the oven. 

When the molds are properly dried, 
they should be removed from the oven, 
placed on the pouring floor, and have the 
dust blown out with compressed air. 

Now set the cores, close the molds, and clamp along joint flanges. 
Set runner boxes over the runners, and tuck heap sand around to 
prevent leakage. In pouring, a mold is filled only to the level of 




Fig. 149. Section of Steel Ladle 




Fig. 150. Runner Box for 
Steel Mold 



144 



FOUNDRY WORK 



the top of the risers. The metal drains from the runner box, thus 
allowing it to be used more than once. 

Cleaning Castings. Steel castings do not run as smoothly as 
cast-iron ones, but they have this advantage, that, if they show only 
slight surface defects, the metal may be peened over with a hammer 
to improve appearance. The intense heat makes the metal burn into 
the sand greatly, so that cleaning is much more difficult, and the 
sand often must be almost cut from the castings by means of long 
cold chisels, struck with sledges. Pneumatic hammers are used to 
a large extent in cleaning and in removing fins and slight projections. 
Where shrinkage webs show, they must be cut out. Steel does not 
break off as does cast iron. The heavy gates and risers must be 




Fig. 151. Cutting Off Riser 

removed by metal saws, as shown in Fig. 151, or by drilling a number 
of 1-inch holes side by side through the base of the riser and then 
breaking it off. The castings are generally annealed before the 
risers are cut off. 

Annealing. In all steel castings of any size, cooling strains will 
develop on account of the shrinkage, and these should be relieved by 
annealing. In suitable trench-like ovens, the steel is heated to a dull 
redness. This allows the grain to assume normal conditions. The 
heating is usually done with a wood fire. Overheating renders the 
grain coarse, and weakens the casting. As indicated by the following 
figures, proper heat-treatment materially increases strength and 
toughness, and the work which is properly annealed is not only 
actually stronger, but being tougher, will stand more hard usage. 



FOUNDRY WORK 



145 



Conditions 


Tensile 

Strength 

[\h. persq.in.) 


Elongation 
(per cent) 


Reduction 
op Area 
(per cent) 


Raw 

Annealed 

Improperly annealed 


80,360 

81,767 
79,421 


13.31 

27.6 

14.3 


16.2 
40.4 

17.8 



MALLEABLE PRACTICE 

Development. It is believed that early attempts to soften hard 
castings by reheating them, and the collection and publication of 
the results of these operations in 1722, by Reaumur, which led to the 
taking out of patents on the process by Lucas in 1804, comprised 
the early history of the malleable-iron industry 

Seth Boy den of Newark, New Jersey, produced the first mal- 
leable iron in America. It is recorded that in 1828, The Franklin 
Institute of Philadelphia, Pennsylvania, awarded him a premium 
for the best specimens of annealed cast iron. These were mainly 
harness trimmings. 

Before 1890, the secrets of the process of malleableizing were 
closely guarded, which accounts for its slow growth, but since then 
great advances have been made both in quality and tonnage, due to 
a better knowledge of the principles involved. As the industry 
now stands it is farthest advanced in the United States. It is 
estimated that for the year 1907 the output for all Europe was but 
50,000 tons as compared with a production of 980,000 tons in America 
for the same year. 

It is rather surprising that, while there is more skill required to 
produce malleables — and there are several extra operations — the price 
is so little in advance of that for gray iron. This is accounted for in 
part by the large number of castings ordered from a given pattern. 

Comparative Characteristics of MetaL An idea of the value of 
this material is best obtained by a comparison of its properties with 
those of similar substances. Thus, gray-iron castings range from 
those nearly black in fracture, to white, with all degrees of softness 
up to glass hardness. They may be strong or weak and still serve 
their purpose. The desirable characteristics of the gray-iron casting 
is its extreme resistance to compression. Where great shock is to be 
cared for, great massiveness is required. 



146 FOUNDRY WORK 

The steel casting has the highest strength of any cast metal: 
it may be deformed considerably without danger, and is cheaper than 
a corresponding forging. 

The malleable casting is the connecting link between the two 
above mentioned. It is stronger than the gray casting but not as 
strong as cast steel. It can be bent or twisted considerably without 
breaking, and approaches gray iron in compressive strength; but its 
most valuable characteristic is resistance to shock. This property 
is best illustrated by the car coupler, a large number of drop tests 
having shown the value of the malleable coupler as compared with 
one of cast steel. 

TESTING 

Methods. There are two general ways for testing malleable 
cast iron: (1) by so-called shop tests; and (2) by laboratory tests of 
bars cast from every heat and annealed with the castings. 

Shop Tests. The usual shop tests consist of bending occasional 
castings, as well as of twisting the longer pieces, and also of the 
making and breaking of test wedges. These wedges are about 6 
inches long and 1 inch square for 3 inches of their total length, then 
tapering down in thickness to nothing for the last 3 inches, but 
keeping the full inch width; this gives thick iron as well as thin on 
the same piece. When the test wedges come from the annealing, 
they should be broken on an anvil by striking them with short light 
blows, the object being to see how much the thin end of the wedge 
can be bent before the piece breaks, after which, by holding the two 
parts together and observing the bend, a very fair idea of the quality 
of the castings these wedges represent, may be had. 

Laboratory Tests. The regulation test bars are rectangular in 
form and are of two sizes: the 1-inch square bar to represent castings 
i inch thick and over; while a 1- by |-inch section bar cares for the 
lighter castings. 

The following specifications adopted by the American Society 
for Testing INIaterials form the only official standard in existence. 

Specifications for Malleable Cast Iron 

Process of Manufacture. Malleable-iron castings may be made by the 
open-hearth, air-furnace, or cupola process. Cupola iron, however, is not 
recommended for heavy or important castings. 



FOUNDRY WORK 147 

Chemical Properties. Castings for which physical requirements are 
specified shall not contain over 0.06 per cent of sulphur or over 0.225 per cent of 
phosphorus. 

Physical Properties. (1) Standard Test Bar. This bar shall be 1 inch 
square and 14 inches long, cast without chills and left perfectly free in the mold. 
Three bars shall be cast in one mold, heavy risers insuring sound bars. 

Where the full heat goes into the castings, which are subject to specifica- 
tion, one mold shall be poured 2 minutes after tapping into the first ladle, and 
another mold shall be poured from the last iron of the heat. 

Molds shall be suitably stamped to insure identification of the bars, the 
bars being annealed with the castings. Where only a partial heat is required 
for the work in hand, one mold shall be cast from the first ladle used and another 
after the required iron has been tapped. 

(2) Of the three test bars from the two molds required for each heat, one 
shall be tested for tensile strength and elongation, the other for transverse 
strength and deflection. The other remaining bar is reserved for either tensile 
or transverse test, in case of failure of the other two bars to come up to require- 
ments. The halves of the bars broken transversely may also be used for the 
tensile test. 

(3) Failure to reach the required limit for the tensile test with elongation, 
as also for the transverse test with deflection, on the part of at least one test, 
rejects the castings from that heat. 

(4) Tensile Test. The tensile strength of a standard test bar for casting 
under specification shall not be less than 40,000 pounds per square inch. The 
elongation measured in 2 inches shall not be less than 2| per cent. 

(5) Transverse Test. The transverse strength of a standard test bar on 
supports 12 inches apart, pressure being applied at the center, shall not be less 
than 3,000 pounds with deflection at least ^ inch. 

Test Lugs. Castings of special design or special importance may be 
provided with suitable test lugs at the option of the inspector. At his request, 
at least one of these lugs shall be left on the casting for his inspection. 

Annealing. (1) Malleable castings shall neither be over- nor under- 
annealed. They must have received their full heat in the oven at least 60 hours 
after reaching that temperature. 

(2) The saggers shall not be dumped until the contents shall be at least 
black hot. 

Finish. Castings shall be true to pattern, free from blemishes, scale, or 
shrinkage cracks. A variation of xe inch per foot shall be permissible. Found- 
ers shall not be held responsible for defects due to irregular cross-sections and 
unevenly distributed metal. 

Inspection. The inspector representing the purchaser shall have all 
reasonable facilities given him by the founder to satisfy him that the finished 
material is furnished in accordance with these specifications. All tests and 
inspections shall be made prior to shipment. 

In general it may be said it is not necessary to have a metal 
very high in tensile strength but rather one which has high transverse 
strength and good deflection. This means a soft ductile metal which 



148 FOUNDRY WORK 

adjusts itself to conditions more readily than a stiff strong product, 
for it is very hard to produce a strong and at the same time soft 
material, especially in the foundry making only the lighter grades of 
castings. 

PRODUCTION PROCESSES 

Preparing Molds 

Patterns. One of the most important departments of the 
malleable works is the pattern shop. Malleable castings are com- 
paratively light when considered in connection with general gray- 
iron practice and m.any times are ordered in enormous quantities 
from the same pattern. 

Every refinement in pattern-making for light castings is found 
in this branch of the foundry industry. When developing a new 
article, the pattern-maker must practically I've in the foundry. 
As trial castings are made he must measure them up with the pattern 
and make changes as found necessary; he must try them out again 
both before and after annealing, and with iron from different parts of 
the heat, and thus bring out new points calculated to help the molder 
and to lessen difficulties from shrinkage. It is the rule never to start 
an order for a quantity until the pattern has been tried out, the hard 
castings have been broken for evidence of shrinkage, and everyone 
has been satisfied it is safe to proceed. 

Construction Difficulties. The terms shrinkage and contraction, 
as applied to malleable castings, should be clearly understood before 
any further mention is made of this subject. While shrinkage in 
gray-iron practice is often considered as the shortening of a casting 
in cooling, in malleable practice shrinkage means the tearing apart 
of the particles of iron in the interior of a larger section, close to a 
small one, leaving a spongy mass which is weak and very dangerous 
to the life of a casting. Contraction being simply reduction in size 
while the casting is cooling, amounts roughly to | inch per foot in 
the hard, i.e., before annealing. During the annealing, about half 
of this is recovered, so that the net result is about the same as in gray- 
iron practice. It should be plain, however, that this big contraction 
causes the tearing as above mentioned when there ^re heavy sections 
which remain in a molten state a little longer than do adjoining 
light sections, unless liquid iron can be fed in. Where this is impos- 



FOUNDRY WORK 



149 



sible, the use of chills must be resorted to and fillets made much 
larger. 

In gating patterns it is to be remembered that white iron chills 
easily and must be poured rapidly. To a certain extent, this limits 
the number of pieces that may be run successfully, unless the gates 
be made so large there would be danger of dirty castings. The run- 
ners should be large and the sprues heavy, the idea being to get a 
large amount of metal in front of the gate for the individual casting. 
The use of the match 
plate is largely resorted 
to also, as being well 
adapted to this class of 
work. Fig. 152 shows a 
group of three of the 
gated patterns in daily 
use in the Arcade Mal- 
leable Iron Foundry, 
Worcester, Massachu- 
setts. In Fig. 153 there 
are shown 84 small 
thumb nuts on one gate ; 
also 18 hinge patterns 
mounted on a match 
plate. 

Molding Methods. 
But little difference from 
ordinary gray-iron meth- 
ods, occurs in molding 
practice other than in 
gating and in pouring. 

Since white iron melts at a somewhat lower temperature, there is 
less danger of sand burning into the casting, so less attention is paid 
to facing sand, 

A large per cent of the work is made in the snap flask on th.^ 
bench, as illustrated in Fig. 154. From the fact that nearly all 
work is in quantity, here is where molding machines may be used to 
great advantage. As these are explained elsewhere, no more need be 
said except that care should be exercised in the selection of types 




Fig. 152. Gated Patterns 



150 



FOUNDRY WORK 




Fig. 153. Typical Gated Pattern and Match Plate 




Fig. 154. Molds lu Pu«iliun for Pouring 



FOUNDRY WORK 



151 




Fig. 155. View of Molding Floor, Fig. 154, Taken from Opposite End of Plant 



.r~i 




Fig. 156. Sand-Mixing Machine 
Courtesy of Standard Sand and Machine Company, Cleveland, Ohio 



152 FOUNDRY WORK 

best suited to local conditions. Fig. 155 is a view from the opposite 
end of the same foundry floor. 

Flasks. While much of the work is handled in snap flasks, it 
is not unusual to find metal flasks closely conforming to the shape 
of the pattern, thereby greatly reducing the amount of sand to be 
handled, with a corresponding reduction in cost of production. 

Cores. Practically all castings are cored and the problem is 
to produce a sufficient number of cores, that there may be no delay 
for the molder. As there is no important difference in the preparation 
.of cores — the same sand and binders being used — the large number 
required warrants the introduction of modern sand-handling and 
mixing machinery to a somewhat greater extent than in gray iron. 




Fig. 157. Mixing Paddles of Standard Sand-AIixing ]\Iachine 

The batch mixer alone proves of great value by the reduction of 
binder required due to its more even distribution; oftentimes this 
amounts to nearly 100 per cent. The type of batch mixer shown 
in Fig. 156 is made by the Standard Sand and INIachine Company, 
Cleveland, Ohio. Fig. 157 is a view of the mixing paddles. 

Melting Metal 

Methods of Melting. Under this head the several methods in 
use will be described, which are as follows: (1) crucible; (2) cupola; 
(3) air-furnace; and (4) open-hearth. 

Crucible Melting. The quality of metal produced by this method 
is without doubt of the best. Being melted out of contact of the 
fuel, there is no danger of absorbing impurities therefrom, but the 
small amount of metal available at one time limits the production 
to only the smaller work. Partly for this reason, the excessive cost of 



FOUNDRY WORK 



153 



production does not admit of competition with other methods which, 
while lacking somewhat in quality, yet meet actual requirements. 




Fig. 158. Air Furnace with Bath, at End Remote from the Bridge 

A more detailed description of melting in the crucible is given in 
the subsequent section on Brass Melting. 




Fig. 159. Longitudinal Section of Air Furnace with Bath Immediately 
behind the Bridge 

Cupola Melting. As in gray iron, the cupola offers the most 
economical method of melting iron, not only in cost of installation 



154 



FOUNDRY WORK 



and saving of fuel, but in ease of manipulation as well. It has some 
disadvantages which restrict its use, the greatest being the inferior 
quality of metal produced, which is caused by the contact of metal 
with the fuel, and also the danger of burned iron which in turn makes 
sluggish iron, with the result that castings are likely to show pin- 
holes. 

There is also greater difficulty in annealing — usually it requires 
200 or 300 degrees Fahrenheit higher temperature. This method may 
be safely used only when the property of bending, rather than 
strength, is required. Pipe fittings form a large part of the pro- 
duction of the cupola method. However, it makes a convenient 
melting medium for the production of anealing boxes. 




Fig. 160. Section of Roof of Air Furnace 



Air-Furnace Melting. The number of furnaces of this type far 
exceeds all others. In the issue of the Foundry Magazine for Feb- 
ruary, 1910, the number of the different types of furnaces engaged in 
the production of malleable in America was given as follows: air 
furnaces, 369; cupolas, 42; open-hearth furnaces, 21. 

Figs. 158 and 159 show two general types of air furnace. In 
the furnace represented in Fig. 159 the bath is immediately behind 
the bridge, while that shown in Fig. 158 has its bath at the end, 
remote from the bridge. 

Fuel is placed on the gate through the charging door D, which is 
of cast iron lined with fire brick. The hearth // is where the metal 
is placed when charged. E is the stack through which the gases 



FOUNDRY WORK 



155 



finally escape. B is the bath where the molten metal collects and at 
its lowest point the tapping hole is located. The metal is charged by 




Fig. 161. Complete Installation of Air Furnace 



removing a part of the roof as shown at 0, a section of which is shown 
in Fig. 160. Peepholes are shown at PPP, w^hich are for observation. 




Fig. 162. View Showing Method of Firing Air Furnace 

The iron is charged on the hearth so as to leave openings between 
the pieces, and the molten metal should be skimmed from time to 



156 



FOUNDRY WORK 



time so that it may receive the direct action of the burning gases 
passing over it. 

Fig. 161 shows a type of air furnace complete. Fig. 162 is a view 
of the opposite side with a melter in the act of firing. Fig. 163 shows 
the slag hole, and the slag just skimmed off. 

The air furnace requires greater skill to operate than does the 
cupola, and the fuel ratio is higher, but, if of good quality and 




Fig. 163. Slag Hole 

properly fired, is not excessive and should average about 3 of metal 
to 1 of fuel. 

Open- Hearth Melting. It is said the open-hearth installation 
represents the highest type of melting yet devised, but the high 
first cost, combined with frequent and heavy repairs and skill required 
to operate, confine its use to the largest plants, and as long as the 
trade is satisfied with the quality of the product of the more easily 
operated air furnace, it is quite doubtful if the open hearth will be 
generally adopted. The description of the open-hearth furnace which 
has been given in Steel-Casting Practice may be referred to. 

Iron Mixture. Without the proper mixture of iron no furnace 
will produce satisfactory iron, hence the importance of using the 
greatest care in this part of malleable practice. 



FOUNDRY WORK 



157 



That the reader may clearly understand the basic principles 
involved, it is necessary first to discuss the various materials entering 
into the mixture. These include pig iron, sprues, faulty castings, 
annealed scrap, steel scrap, and ferro-alloys. 

Good Composition. As all the materials have a bearing on the 
finished casting and should only be used as they affect this, it is at 
this time well to give an analysis for good malleable castings, which 
is as follows : 



Element 


Proportiox 
(per cent) 


Silicon 

Carbon 

Sulphur 

Manganese 

Phosphorus 


0.75 to 1.25 

3.00 

0.04 (extreme) 

0.60 (extreme) 

0.20 (extreme) 



There is considerable latitude allowed due to the class of work to 
be produced. Makers of heavy castings exclusively may specify 
their silicon from 0.75 to 1.50 per cent, while for very light work 
silicon from 1.25 to 2.00 per cent may be the rule. Total carbon 
shou d never run below 2.75 per cent in the hard, i.e., before the 
annealing. Manganese should average about 0.40, not much lower, 
and never above 0.60. Sulphur should always be as low as possible, 
0.07 per cent being the high limit in the casting, hence the necessity 
for choosing irons for the mixture which will insure this. Phos- 
phorus below 0.225 per cent is desired. 

Pig Iron. Formerly it was thought that only charcoal pig was 
suitable for malleable practice, but today, owing to improved blast- 
furnace practice, coke irons which are known to the trade as cohe 
r.ialleable give first-rate results and are used to a considerable extent, 
yet it is seldom that the writer has heard of a mixture that did not 
include one or more of the well-known brands of charcoal iron known 
to the trade as Mabel, Briar Hill, Hinckley, and Ella. It is generally 
conceded that a mixture containing several brands of iron, or at least 
two or three grades of the same brand, produces better castings. 

Scrap, The next problem which presents itself is the dispo- 
sition of gates, sprues, and discards, which are daily accumulated 
in the works, and the per cent of which varies with the class of vrork 



158 FOUNDRY WORK 

produced, running as high as 60 per cent in the hghtest work or not 
exceeding 25 per cent for very heavy castings. From this it will be 
seen that it is quite likely to be a varying element. The practice 
of taking the silicon content for every heat before castings go into 
the annealing operation gives opportunity for fairly exact calcu- 
lations. Corrections may be made in the mixtures as may be found 
necessary, otherwise, should there be an accumulation of such 
material, it would soon become an unknown quantity and so be a 
source of annoyance as well as of loss to the management. 

The annealed scrap offers more difficulties owing to the effect 
which even small amounts have on the quality of the product. Quite 
frequently there is no attempt to use this in the regular mixture but 
rather to utilize it in the production of annealing pots of which more 
will be said later. 

The use of steel scrap in malleable mixtures is proving beneficial 
although the amount is at present limited to something like 10 per 
cent. This material should not be charged with the regular mixture, 
but should be introduced into the bath of molten metal so that it may 
be quickly covered by the protecting slag, for the steel must not be 
allowed to burn as this would seriously injure the quality of the 
castings. 

It is also possible to use small amounts of gray-iron scrap, 
though it is seldom necessary to do so, and usually 5 per cent is the 
limit. 

Ferrosilicon. This material is carried in stock, either as a 0.50 
or 0.75 per cent alloy for use in the ladle, or as a 14 to 20 per cent 
pig for use in the furnace. 

In choosing metals for the heat it first is necessary to ascertain 
the silicon content desired in the castings, and then to select such 
amounts of the different brands of pig iron at hand as are required 
to bring about the desired result, first making careful calculation of 
the amount of scrap to be cared for and its effect on the mixture as 
regards its silicon content. The previous section on Melting may 
be referred to regarding gray-iron mixture. 

In conclusion, -it would be well for the reader to clearly under- 
stand that it requires greater skill to produce malleables, and for 
this reason a well-equipped laboratory and a good metallurgist are 
almost necessities where high quality is the order of the day. 



FOUNDRY WORK 159 

Malleable Casting 

Variation from Qray=Iron Practice. The furnace having been 
duly charged for the day's melt with the desired mixture of metal, we 
will now consider the casting operation which differs only from gray- 
iron practice in that the metal contains a larger per cent of carbon 
in the combined form, melts at a lower temperature, and also cools 
more quickly in the ladle, and for this reason must be handled more 
rapidly. The hand ladles are of somewhat smaller capacity, usually 
about 25 pounds, as compared with 40 to 60 pounds in gray-iron 
practice. 

Carrying. This lighter burden allows the molder greater free- 
dom in his movements. It is common practice to see the molder 
catching-in to the stream of molten metal and running to his floor 
that the molds may receive the benefit of the hottest metal possible. 
While this is possible in malleable-iron work, with the larger 
ladles of gray-iron practice, this would not only be exhausting, but 
highly dangerous as well. 

It must be remembered that the majority of work is light and 
that the floor space required for the setting-up of sufficient molds to 
pour, say, a 30-ton heat, is considerable, and even with the furnace 
located as it should be in the center of the w^orks, there must be long 
carries. These are in part overcome by the installation of some 
overhead trolley system using 500-pound ladles; and where the 
nature of the work permits — i.e., it is not too light — this method is 
of course preferable. 

Cooling, As there is great danger of the castings developing 
cracks if exposed to the air while still red hot, it is far better practice 
to let them remain in the sand until they are at least black hot when 
they may be safely shaken out: the exception being some special 
work, as brake wheels, for example, in which there are developed great 
casting strains. In this case it is found best to shake out while still 
red hot and quickly place them in a so-called reheating oven which is 
already fired very hot. This furnace, after being fully charged with 
the day's output of this special work, is closed and the fire allowed 
to die out over night, when the castings will be found to be partly 
annealed, though not in a malleable sense. This treatment is found 
of considerable value in certain classes of work which otherwise 
might be hard to save. 



160 



FOUNDRY WORK 



Cleaning Castings. The castings having become cool so that they 
may be readily handled, a rough separation of castings and gates 
should be undertaken and the cores removed as far as possible, after 
which the castuigs should be inspected and all missruns or otherwise 
defective castings removed. The discards along with the gates and 
sprues should then be tumbled to remove the sand scale before being 
returned for remelting, otherwise it would form an excessive slag and 
require a larger amount of fuel to remelt. 




Fig. 164. IModern Exhaust Tumbling Barrel 



Hard-Rolling. After this rough sorting the castings are ready 
for the hard-rolling room which contains a series of tumbling barrels, 
all of which should be equipped with an exhaust system, or else the 
dust created m this department will become the bane of the plant. 
Fig. 164 shows an installation of modern exhaust tumbling barrels. 

The castings should be rolled only long enough for the removal 
of the sand scale, usually accomplished in from 20 to 30 minutes. 
Some classes of work may be so delicate that it would be impossible 
to clean them in this manner without too great a loss from breakage, 
and in such cases the acid bath may be resorted to, or perhaps the 



FOUNDRY WORK 



161 



sand blast which is fast superseding other methods of cleaning all 
classes of castings. Fig. 165 shows a New Haven sand-blast tumbling 
barrel which is well adapted to this work. 

After this hard-rolling process the castings are removed to the 
trimming room where the gates and fins remaining may be easily 
removed with a hammer, thus saving much time in the grinding room 
after the annealing. 

Annealing. We now arrive at one of the most important depart- 
ments of the plant. No matter how carefully all previous operations 
may have been conducted, all will have been in vain should any 



1 


m ''"t 


i 




^H^^H^^H 


1 
■1 


4" 


R 


m 




W^^KkK^^^E^K <' 


1 


3 

&^^^ 




1 


it:^v^ 


^^^^Lk^ 


i 



Fig. 165. Sand-Blast Tumbling Barrel 

neglect creep into this part of the practice, for it is here that the very 
nature of the casting is changed from its hard and brittle state showing 
a white fracture, to the so-called black-heart malleable, the fracture 
showing a steely rim with a black velvety core. 

This change is brought about by gradually bringing the tem- 
perature in the annealing ovens up to about 1600 degrees Fahren- 
heit, and by maintaining that temperature from 3 to 4 days, after 
which the fire is allowed to slowly die down; this whole process requires 
from 8 to 10 days. There have been attempts made to shorten this 



162 



FOUNDRY WORK 



annealing process, usually by increasing the temperature some 200 
degrees, thereby reducing the total period of the process to about 6 




Fig. 166. Packing Annealing Boxes 




Fig. 167. Hand Cliarging Truck 



days; but this has been done at the expense of quality, and the best 
results are obtained by the former method. 

Preparation of Castings. After inspection in the trimming room, 
the castings are brought to the annealing room which has its floor 



FOUNDRY WORK 163 

space divided into two parts — the packing floor, and the ovens. 
There are usually two rows of ovens, one on each side of the build- 
ing, and the clear space between is used for packing the pots and 
also for dumping them after the annealing. The floor of this is made 
of 1-inch iron plates. 

The annealing boxes, or laggers, may be either square or round, 
or perhaps more generally oblong, and are first cast 1 inch thick. 
These pots are piled three or four high — the first one is placed on 
an iron stool — all joints being luted up with mud made by adding 
water to the burnt sand from the rolling room with perhaps the 




Fig. 168. Interior View of Annealing Oven 

addition of a little fire clay. The scale used for packing is cinder 
squeezed from muck balls where wrought iron is made. It was 
formerly the practice to spread this scale upon the floor and sprinkle 
it daily with a solution of sal ammoniac to rust it, but later-day 
practice has proven this unnecessary. 

As the castings come into the annealing room the operator 
places a pot on the stool, shovels in some scale, carefully placing in a 
layer of castings in such manner that none comes in contact with 
the sides of the pot or no two castings touch each other, then more 
scale and more castings are added until the pot is filled, as shown 
in Fig. 166. On this another pot is placed and duly packed, this to 



164 



FOUNDRY WORK 



be continued until the pots are piled as high as desired, after which 
all joints are sealed with mud making the whole pile more or less 




Fig. 169. Oven Charged 




Fig. 170. Ash Pit and Firing Doors 



air-tight. After this has been accomplished, the pots are placed in 
the oven either by a hand or by a power charging machine, as 
illustrated in Fig. 167. 



FOUNDRY WORK 



165 



Oveji. The annealing oven is quite simple. . The principle 
involved is the introduction of heat from some convenient point 
and its distribution in a uniform manner, and the introduction of as 




lig. 171. Final Sorting of Castings 




Fig. 172. Shipping Room 



little air as possible. The combustion space should be no larger 
than necessary, the draft regulation perfect, and the bottom of the 
oven underlaid by a series of flues which allow the gases to circulate 



166 



FOUNDRY WORK 



before escaping into the stack, so there may be as Uttle loss of heat 
as possible. Oil, gas, or coal may be used for fuel as best adapted 
to the locality. 

Fig. 168 shows the interior of an oven, while Fig. 169 shows 
the boxes in place. Fig. 170 is a side view of an oven showing the 
firing doors and the ash pits. Having placed the full number of 




Fig. 173. Recording Pyrometer 
Courtesy of The Bristol Compayiy, Waterbury, Connecticut 

boxes in the oven, the front is closed and the ovens are fired. As 
before stated this operation requires from 6 to 10 days from the time 
the fire is started until the oven has cooled sufficiently to allow the 
removal of the boxes. 

As the boxes are withdrawn from the oven and are taken to the 
floor of the annealing room, they are suspended from an overhead 
trolley, or by a crane, and the castings are removed by striking the 



FOUNDRY WORK 167 

boxes several sharp blows with a medium-weight sledge hammer, 
the castings and scale falling upon the floor. The castings are now 
picked from the scale and it will be noted that there is some tendency 
for the scale to adhere to them. This may be removed by the 
ordinary rolling barrels, after which any gates or fins remaining 
should be ground off. The amount of labor required for this oper- 
ation depends upon how carefully the gates were moved while castings 
were in the hard. After a final inspection, the castings should be 
ready for shipment. Figs. 171 and 172 show" the castings being 
sorted out and ready for shipment in the shipping room. 

Pyrometer. The use of the pyrometer in connection with the 
annealing furnace is almost obligatory. Fig. 173 shows a standard 
type of recording pyrometer. The pyrometer equipment is often 
placed in the ofiice of the head executive of a local plant; it is pos- 
sible for him to plug into any two of his battery of annealing 
furnaces at any time during the day. Also, in the morning, there 
is recorded a true record of temperatures for the night before. As 
no operator knows whether his furnace is under observation or not, 
this system has the tendency to keep the men at all times alert. 

Finishing. The amount of finish given the castings varies 
with local conditions and class of castings produced. There are some 
classes of work where, by the use of leather scraps in the soft-rolling 
room, the work is so carefully cleaned and polished that the castings 
may be tinned or nickeled and sometimes gold- or silver-plated, 
making very beautiful work in which great strength is combined with 
cheapness of production. 

BRASS WORK 
ALLOYS 

Distinctions. Cast iron, cast steel, and malleable iron, which we 
have previously considered, are three forms of the same metal — iron. 
The difference in their physical characteristics is due solely to a 
variation in the proportions of certain elements or metaloids combined 
with the iron. 

The metals to be dealt with in this section are termed alloys — 
that is, mixtures of two or more separate metals. The common 
alloys in use in the foundry, for casting various machine parts, are 



168 FOUNDRY WORK 

made from combinations of copper, tin, and zinc, and are called 
brass, or bronze. 

Brass and Bronze. Although the term brass is held by some 
authorities to cover any of these combinations, the general classifica- 
tion accepts brass as an alloy of copper and zinc, and bronze as an 
alloy of copper and tin. In some sections the latter is spoken of as 
composition. 

Bronze has been used by man in all ages. Centuries before the 
Christian Era the Egyptians employed it for making coin, armor, 
and weapons, as well as household utensils, and statuettes of their 
gods. Analyses of many of these ancient relics show the composition 
to be almost identical with the bronzes of the present day. Brass 
also was in use before the time of Christ, but unquestionably bronze 
was of earlier origin. 

Metals. A short discussion of the separate metals will help in 
understanding the properties of their alloys. 

Copper. Copper has a red color; it is hard, ductile, and very 
tough. It melts at about 2000 degrees F. ; but it is difficult to make 
castings of the pure metal. Copper does not rust as does iron, and 
is one of the best conductors of heat and electricity. For this reason 
it is largely used in sheet form as a sheathing metal, and in the form 
of wire or rods for electrical transmission. Casting copper is put 
on the market in ingots of special form weighing from 18 to 25 
pounds each. 

Tin. Tin is a white lustrous metal, very malleable, but lacking 
tenacity. It may be reduced extremely thin by rolling, as is shown 
by tin foil. It melts at 450 degrees F. When a bar of tin is bent 
it will give a crackling sound known as the cry, which at once dis- 
tinguishes it from other metals such as solder, lead, etc., which have 
similar external appearance. It is put on the market in pigs weighing 
about 30 pounds and also in bars of about 1 pound each. Its cost is 
approximately IJ times that of copper and 5 times as much as zinc. 
Tin may be cast unalloyed, and is sometimes used to run pattern 
letters or small duplicate patterns cast in zinc chill molds. The 
addition of J to J by weight of lead gives a cheaper metal, however, 
and one that will run equall}^ well. 

Tin mixed with copper gives greater fluidity, lower melting 
point, and greater strength, changing the color from red to bright 



FOUNDRY WORK 169 

yellow. Serviceable alloys may contain as high as 20 per cent of tin. 
This gives a metal of golden yellow color, very hard, tough, and 
difficult to work. With larger percentages of tin the color shades to 
gray, the metal is hard, brittle, and has little strength, and has no 
value for engineering purposes. 

Zinc. Zinc has a bluish white color; it is hard, but weak and 
brittle. The fracture shows very large crystals of characteristic 
shape. It melts at about 700 degrees F., and shrinks but little 
in cooling. For this reason it may be used to cast directly for small 
metal patterns to form chills from which soft-metal castings may be 
made for duplicating these patterns. If exposed to the air at high 
temperatures, zinc will volatilize, that is, turn to a gas and burn. 
It burns with a bluish flame, and throws off clouds of dense white 
smoke. For this reason great care must be used to keep the air away 
from it as much as possible when being melted or mixed in an alloy, 
for, aside from the loss of metal, an oxide is formed in the mixture 
which impairs the quality of the alloy. 

Zinc is known in commerce under two names: when rolled into 
sheets it is called zinc; when in ingot form for casting, it is called 
spelter. These ingots are flat, approximately 8 by 1 by 17 inches, 
and weigh about 30 pounds. In this form they may be easily broken 
in small pieces for convenience in charging. 

Zinc may be added to copper in a very wide range of proportions, 
the alloy increasing in hardness and losing ductility with the increase 
in the proportion of zinc. The color changes from the red of the cop- 
per to a full yellow when J zinc is used. Further additions of zinc 
change the color to red, yellow, violet, and gray. The alloys are 
serviceable up to 40 or 50 per cent of zinc. 

When zinc is mixed with melted metal, considerable reaction or 
boiling takes place, which tends to make a more thorough mixture 
and to drive impurities to the surface. For this reason a small pro- 
portion of zinc — 2 or 3 per cent — is often stirred into bronze mixtures 
after the pot is drawn. 

Lead. Lead has a bluish white color, and considerable luster 
when freshly cut. It is malleable, soft, and tough, but very weak. 
It melts at about 600 degrees F. 

Lead is not used by itself as an alloy with copper. A very small 
proportion may be added to the standard mixture for brass or bronze. 



170 



FOUNDRY WORK 



TABLE VI 
Proportions of Mixtures 





COPPEB 


Tin 


Zinc 


Lead 


Jla-p 














USE 


/per \ 
Vcent / 


(ounce) 


/per\ 
V centy 


(ounce) 


(cent ) 


(ounce) 


/per \ 
V cent; 


Counce) 


Gun metal — for bearings; 


















very tough hard mix- 


















ture ■ 


83 


16 


12 


2h 


2.5 


h 


2.5 


i 


Steam or valve metal — 


















cuts freely; very tough; 


















resists corrosion 


85 


16 


7 


u 


5 


f 


3 


\ 


Composition metal — for 


















general use on small 


















machine parts 


90 


16 


5 


1 


5 


h 






Art bronze — rich color; 


















runs fluid at compara- 


















tively low heat 


90 


16 


6 


1 


3 


1 


1 


\ 


Common yellow brass — 


















for general run of ma- 


















chine castings 


66.5 


16 






33.5 


8 






Brass — to machine easier 


















than the above; for 


















same purposes 


66 


16 


33 






8 


1 


\ 


Antifriction metal — f o r 


















journal boxes 


1.8 


1 


64.7 


32 


33.35 


16 


1 


\ 


Mixture — for small pat- 


















terns; runs weh; shrinks 


















little 






66 


2 






34 


1 



It will cause them to run more fluidly in pouring, and be softer for 
machining. For this reason, lead is added to bearing mixtures to 
advantage. But it tends to deaden the color and reduce the conduc- 
tivity of the metal for electrical purposes. 

Mixtures. General Proportiojis. The percentages given in 
Table VI are for convenience in comparison and for figuring large 
heats. The beginner, however, will generally melt but 1 or 2 pigs of 
copper at one time. These he will weigh first, and then figure the 
other portions of his mixture from this weight. In this case a 
formula given in pounds and ounces is much simpler. 

Variation. From what has been said, it is understood that it 
is possible to vary these mixtures to meet special conditions. To 
harden or toughen an alloy, increase the' tin; to soften it, reduce the 
tin. The same is true with zinc, but it will require larger proportion- 
ate changes in this metal to effect similar results in the alloy. 

Phosphorus. Phosphorus is not a metal, but is a very active 
chemical element manufactured from bone ash. It has such af» 



FOUNDRY WORK 

TABLE VII 
Phosphor=Bronze Mixtures 



171 



Element 


Proportions op Alloy 


Hard 


Tough 


;per cent) 


(pounds) 


'per cent) 


(pounds) 


Copper 
Tin 

Phosphorus 
Phosphor tin 


87.5 
12.25 

0.25 


81 

3 

1 


90. 
9.75 
.25 


9 


Total 


100. 


10 


100. 


10 



affinity for the oxygen of the air, that in its pure state it must be kept 
under water, because the sKghtest scratch would cause it to burn 
fiercely. It forms the principal substance used in making the heads 
of matches. 

As a rule it is never used in the foundry in its pure state. For 
the production of phosphor-bronze castings there are several combined 
forms of phosphorus on the market. The most convenient of these 
is known as phosphor tin, which is metallic tin carrying various 
fixed percentages of phosphorus, of which 5 per cent is one very 
common proportion. Know^ing the amount of phosphorus carried 
by the tin, the exact proportion for the entire alloy may be readily 
calculated. This element should not be used in alloys containing 
zinc or lead. 

Phosphorus acts as a flux, combining with any oxidized or burned 
impurities in the bath of metal and driving them to the top. It tends 
to make the tin crystalline in form, in which condition it unites 
more firmly with the copper. It apparently unites chemically with 
copper, making that metal harder. The proportion of phosphorus 
should not exceed 0.75 per cent, while 0.25 to 0.40 per cent are safer 
proportions. 

Two typical mixtures, one using 5 per cent phosphor tin, are 
given in Table VII. 

PRODUCTION 

Molding Materials. Natural molding sands are used for brass 
work. They are usually finer than sands used in iron work, because 



172 



FOUNDRY WORK 



brass parts are generally small and often have fine detail which must 
be brought out very sharply in the mold. For this reason, also, the 
sands should have more alumina or bond than iron sands. This 
increase of bond is possible because the metals entering the 
mold are not as hot as iron would be, and therefore do not require 
as much vent, but they have a greater tendency to cut the mold. 




Fig. 174. 



Flask for Brass; B — Screw Clamp 



For the general run of work the whole heap is kept in good con- 
dition by the frequent addition of new sand, but on large work a 
facing mixture is used similar to that of the iron foundry. 

Burnt sand, powdered charcoal, and partainol are all good 
parting materials; the last two are best on small work, as they make 
a cleaner joint. Since they make a good facing for the mold, they 
are not blown off of the patterns. 




Fig. 175. Spill Trough 

Equipment. Tools. The brass molder uses practically the same 
kind of tools, such as shovels, sieves, rammers, and molder's tools 
generally, as already have been described. 

Flasks, Snap flasks may be used, but the pins, hinges, and 
catches must be kept in careful adjustment so that the parts of the 
mold shall register perfectly. The same is true of the larger box 
flasks for floor work. 



FOUNDRY WORK 



173 



The most typical brass flasks are of cast iron with accurately 
fitting round steel pins, as seen in Fig. 174 at ^. They have holes on 
the joint at one end of the flask so that the mold may be set upright 
when pouring. This gives a decided additional pouring pressure 
with a minimum thickness of sand over the castings. 

Boards without cleats support the sand in the flask, and the 
whole is clamped, before setting on end, by means of some form of 
double-screw clamp similar to the illustration B, in Fig. 174. 




Fig. 176. Drying Stove 



Spill Trough. Great care is taken in the brass shop to save all 
the shot and spifled metal possible. To this end, when the molds 
are to be poured on end, they are leaned against a cast-iron spill 
trough such as shown in Fig. 175. There should be a 1-inch layer 
of sand over the bottom of this tray. The crucible is held over it 
when pouring the molds, thus making it possible to conveniently 
catch, any metal that is spilled. 

Drying Stove, For thin work the face of the molds are skin- 
dried to drive off the moisture before the metal enters the mold. 
Drying stoves, similar to that shown in Fig. 176, are used for this 
purpose. When the mold is finished, the two halves are carefully 



174 FOUNDRY WORK 

sprayed with a weak molasses water, and the flask is set on end on 
the wide platform with the face of the mold next to the stove. When 
sufficiently dry, the mold is closed and poured at once. 

Principles of Work. Size of Heat. Brass work deals, as a rule, 
with smaller quantities in every way than does iron work. The 
patterns are generally smaller, and the brass molder takes particular 
pride in making all his joints so neat that hardly a fin shows on his 
castings. The matter of catching the shot metal has been mentioned. 
Up to the time of the introduction of the oil-melting furnace, it was 
customary to heat a pot of metal for each molder. These heats were 
comparatively small, so that the molder would make up possibly 6 
or 8 molds, then draw his pot and pour them, running in this way 
several heats in a day. Using the furnace, several heats are run 
each day, but a much larger quantity of metal is melted at each heat, 
so that the work of several molders is poured with exactly the same 
metal. 

Molds. A mold for brass should be rammed about the same as 
for iron. On name plates and thin work, after the initial facing of 
sifted sand has been properly tucked with the fingers, the fiask is 
filled heaping full of sand. Then by the aid of a rope hanging down 
from the ceiling, the molder springs up on top of the flask and packs 
the mold with his feet, the weight of his body giving the right degree 
of firmness to the sand. Stove-plate molders often pack their flasks 
in the same way. 

The main differences between making up molds for brass and 
those for iron are due to the three following causes: brass melts 
at a lower heat; it does not run as fluid as iron; it has about double 
the shrinkage of iron. For these reasons the sand may be somewhat 
less porous and still vent sufficiently, if risers are placed to allow for 
the escape of the air. On bench work the vent wire is not used. 
The runners for brass should be larger than for iron, and the gates, 
instead of being broad and shallow, should be more semicircular in 
section. Pouring molds on end gives the pressure necessary to force 
a more sluggish metal to take a sharp impression, and the heavy 
runners shown in the following examples serve to feed the casting 
as it shrinks. Forms of skimming gates, as explained in an earlier 
section, are used to good advantage when the work is of a very 
particular nature. 



FOUNDRY WORK 



175 



Cores for brass work are made up as previously described. To 
give a smoother surface on the small cores, about J molding sand is 
often mixed in with the beach sand of the stock mixture. 

Examples of Work. To illustrate more clearly some of the 
typical methods of brass work, let our first example be a thin flat 
plate with decoration in low relief on one side. 

Place the pattern face down, a little below the center of flask. 
Sift on facing through a No. 16 sieve, then tuck, fill, and pack, as 
previously described. Roll over and make a joint. Now cut a half 
section of the main runners and risers, but do not connect them with 
the mold at this stage. Dust on parting material from a bag, and 
ram the other half of the' flask just hard enough to stand handling. 



-Runner f/?i'3er 




A B 

Fig. 177. A— Mold for Thin Plate; S— Mold for Heavy Plate 

Separate the flask; spray the face of the mold with weak molasses 
water, and dust on it from a bag some finely powdered pumice stone, 
or any fine strong sand, and over this a little parting dust. Now 
replace this half over the pattern, and re-ram to the required firm- 
ness, and again separate and this time draw the pattern. 

The impression of the runners and risers cut in the first half of 
the mold show as ridges on the second half packed, and serve as 
guides for cutting the runners to a full round section. Connect the 
gates in four places, as shown in Ay Fig. 177. Skin-dry the mold and 
dt is ready to close and pour. 

Dusting fine sand on the face of the mold, then reprinting, as it 
ds termed, ensures a very smooth, perfect mold face. Where the 
imbld- is not skin-dried, flour is dusted over the face, allowed to stand 



176 



FOUNDRY WORK 



TABLE VIII 
Crucible Sizes 



Number 








Measurements Outside 


Capacity 
Weight 

OF 

Water 


Holding Capacity 
(Liquid Measure) 


Height 


Diameter 


Top 


Bilge 


Bottom 




(gallon) 


(quart) 


(pint) 


Cinches) 


(inches) 


(inches) 


(inches) 


(pounds) 











2 


u 


If 


H 




0000 








3 1 2f 


2i 
51 


If 




6 




1 




6^ 1 5i 


31 


2.08 


12 




2 




8 ! 6i 


6! 
9i 


5 


4.16 


30 


1 


1 


1 


11 ! 8f 


61 


11.5 


60 


3 






14 lOf 


111 


8 


25 


90 


4 


~2~ 




15i 1 lU 


m 


9 


33.3 


300 


12 




22 1 16i 


m 


m 


104. 



for a short time, and then blown off. This makes a good facing. 

Cutting the heavy runner over the top of the thin plate ensures a 
suflBcient supply of clean hot metal to the gates 
under a large enough pressure to force the 
metal into every detail of the mold before it 
has time to chill. 

In B, Fig. 177, is shown the difference 
in construction of the gate when a heavier 
piece is cast with the flask setting horizontally. 
The gate proper is cut in the drag, but a good 
feeding head is cut out of the cope side to keep 
the metal in the riser liquid until the casting 
has solidified. 

Duplication. For duplicating work, the 
sand match, oil match, or follow board are 
used, the same as for iron work. Fig. 178 
shows a typical set of castings run from the 
end and made from gated patterns set in an 
oil match. Steady pins are placed on the 

gates to facilitate a clean lift. 

Melting. Characteristics. All alloy metals, and especially zinc 

and tin, burn if exposed to the air while melting. To prevent this 




Fig. 178. Duplicated 
Gated Work 



FOUNDRY WORK 



177 



burning the brass melter endeavors to so control the draft in his 
furnace that all oxygen entering the gates combines with the fuel, 
and that the gases which may reach the metal shall contain no free 
oxygen. For this reason, the ordinary brass furnace is a natural- 
draft furnace, although a forced draft is often 
connected below the grates to make combustion 
independent of atmospheric conditions. 

The metal does not come in direct contact 
with the fuel, but is contained in fire-clay pots 
called crucibles, which are bedded in the fire. 
Hard coal or coke is used for fuel. These cruci- 
bles, Fig. 179, A, are manufactured from a very 
refractory fire-clay mixture, and are strong and 
tough, even at a high temperature. They are 
lifted in and out of the furnace by the tongs shown 
at J5, Fig. 179. For the larger sizes a crane is 
used for hoisting the pot. Crucibles are classed 
by number, as seen in Table VIII . New crucibles 
should always be annealed before using, that is, 
brought very slowly to a low red heat. 

Natural-Draft Furnace, Furnaces of this 
type are usually called brass furnaces, and may 
be bought on the market made up in single com- 
plete units. Fig. 180 illustrates one of a battery 
of several furnaces connecting with a common 
flue. The top is on a level with the molding 
floor. The sketch shows clearly the principles 
of construction. A cast-iron bottom plate A, 
with a circular opening, carries a shell of boiler 
plate lined with fire brick. The diameter inside 
the lining should be 6 inches larger than the 
crucible to be used. A top plate, with a similar 
opening, binds the whole together. On one side, 
below the top, the opening B, which may be formed by a cast-iron 
box, connects with the flue or stack. Two heavy ribs cast on the 
bottom plate rest on a pair of rails as shown, and these rails are 
supported by suitable piers of brickwork about 2 feet high, so that 
ashes may be conveniently removed when the furnace is dumped. 



Fig. 179. Crucible and 
Tongs 



178 



FOUNDRY WORK 



In the space made by the ribs, between the bottom plate and the 
rails, the grate bars C are set. These bars are loose and may be 
pulled out when it is desired to dump the fire for the day. 

Operation. Before starting the fire in preparing to run off a 
heat, a good plan is to use a half fire brick on which to rest the 
crucible, or the bottom of a worn-out crucible cut off to the height 
of 4 inches or 5 inches may be turned upside down and used for this 
purpose. 

Sufficient time and special care should be exercised in placing 
the metal in a crucible. It is more or less dangerous to jam in the 
charges, so particular care should be taken to see that they are placed 




Fig. 180. Natural-Draft Furnace 

in the crucible loosely. Graphite is the crucible's principal ingre- 
dient; the only expansion possible to a crucible comes from its clay 
body, hence, if the charges are wedged in a crucible and jammed to 
fit tight, their expansion, which is much greater than the expansion 
of the crucible, cracks the latter before the melting point is reached. 
The crucible should be kept covered, especially for brass. 

In melting brass, melt down the copper first, then the scrap. 
When this is melted, charge the zinc and stir well before lifting the 
pot. Allow the mixture to come to the proper heat again, then pull 
the pot, skim off the dross, and stir in the lead if any is called for, just 
before pouring. In bronze the same method is pursued, but both the 



FOUNDRY WORK 



179 



tin and zinc are stirred in after the pot is drawn. In mixing in the 
zinc in brass, care must be taken to pkmge it well under the surface 




Fig. 181. Section through Oil Furnace 

of the copper with long handled pick-up tongs, and to hold the piece 
down with the stirring bar until it has melted. 

Where a large casting requires more metal than can be melted 
in a single crucible, several furnaces must be used and the contents 
of their various crucibles assembled into one large pouring ladle just 
before pouring. 




OilPump BMyyer V^^^^i^ Me/^/ryg^ Furnace 

Fig. 182. General Views of Oil Furnace 

Gas or Oil Furnace. With the development of natural-gas and 
crude-oil burners for commercial heating, several good furnaces have 
been designed in which a large quantity of metal can be melted at 



ISO 



FOUNDRY WORK 



one time. Fig. 181 shows a furnace of this character in section. This 
type has tandem melting chambers with burners at the end, which 
may be used separately or both together. The w^aste gases from the 




Fig. 183. Sprue Trimmer 
Courtesy of Toledo Machine and Tool Company, Toledo, Ohio 



bath of liquid metal are used to heat up a fresh cnarge in the other 
chamber. The metal is charged and poured from the openings at the 
top of the furnace. Each chamber may be revolved separately, to 



FOUNDRY WORK 



181 




Fig. 184. Dipping Basket 



empty the furnace when the charge is melted. Fig. 182 shows the 
general arrangement of the oil feed pump and blower for these melting 
furnaces. The flame plays directly on to the metal. The oil pressure 
should remain constant at about 5 pounds per square inch. But the 
air pressure is regulated to vary the intensity 
of the heat as desired. 

The pouring ladle must be well heated 
before using. This is done wdth a special gas 
burner, or, when crucibles are used, they are 
often heated by means of a small fire in an 
ordinary furnace. 

Different sizes of furnaces are built to 
melt from 250 to 2000 pounds of metal at a 
heat. Twelve or fourteen heats a day can be run. The saving is 
approximately 50 per cent in time, and is also very considerable in 
expense, over ordinary crucible furnaces of equal capacity. 

Cleaning. When the castings are taken from the sand they 
should be rapped smartly to free all loose sand, then, if machining 
is to be done on them, they should be plunged, while hot, into water. 
This softens the castings. This method is used r„lso to blow out cores 
from small work. 

Since brass does not 
burn into the sand as much 
as iron, the small castings 
in many shops are brushed 
clean, before being cut from 
the gates, by means of a 
circular scratch brush 
mounted on a spindle sim- 
ilar to a polishing wheel. 

A sprue-trimmer, 
shown in Fig. 183, is part 
of the equipment of a brass 

foundry. These machines are made to operate by foot as shown, 
or by power. With them the castings are cut neatly and quickly 
from the runners. 

Pickling. A good method of cleaning brass and bronze is by 
pickling. JNIake a mixture of 2 parts common nitric acid and 1 part 




Fig. 185. Magnetic Separator 



182 FOUNDRY WORK 

sulphuric acid, in a stone jar. Place the piece to be cleaned in a stone 
dipping basket. Fig. 184, and dip once into the acid, then wash off 
in clean water, and dry in sawdust. 

Chip Separation. In many cases, brass chips and filings are 
turned back to the foundry to be remelted. The smallest portions of 
steel or iron in these would prevent their being used in this way, as 
they make extremely hard spots in the castings. 

Fig. 185 shows a magnetic separator which effectively removes 
all steel and iron chips. The brass chips and sweepings from the 
machine shop are placed in the hopper of this machine. They are 
caused to be spread out on one side of a slowly revolving brass covered 
drum. Inside of this brass shell are strong magnets which hold to 
their surfaces the steel and iron chips, while the brass chips drop off 
into a tote box. A stiff brush at the back of the cylinder removes the 
iron chips, and they drop into a separate box. 

SHOP MANAGEMENT 

PLANT ARRANGEMENT 

Governing Factors. The success of a foundry depends upon the 
ability of its managers to promptly turn out castings which meet 
the requirements demanded of them, at the lowest possible cost 
commensurate with the quality of the w^ork. In this article we wish 
to direct the attention of students to some features in the way of 
equipment and management which aid in accomplishing these results. 

The most important processes in the foundry are the following : 
melting metal, making molds, and pouring them. Much of the work 
necessary in preparing for these processes consists in handling heavy 
materials such as coke, iron, sand, etc. To reduce this handling 
to its lowest limits, as to distances, number of re-handlings, and 
methods of conveyance, are problems to be considered in the plan 
of the shop as a whole. 

TYPICAL FOUNDRY 

General Plan. To briefly illustrate some of the points to be 
brought out, let us consider the plan of the shop shown in Fig. 186, 
and its sectional elevation shown in Fig. 187. 



FOUNDRY WORK 



183 



Building. The building is of steel construction, and the columns 
supporting the roof trusses serve also to carry the tracks for the 
overhead traveling cranes. 

The outer walls should be filled in with some good weather- 
resisting material, of which there is nothing better than brick. These 
walls should be of good height and have a sufficient window area to 
supply light well in toward the middle of the shop. 

Ventilation. The method of heating and ventilating best 
adapted for a foundry is the indirect fan system. One or more large 

Upper Level Storage 



Coke Bins 



Pig /r on Yard 




k Mouidingf Machine 



IS- 



Loam 



Dry Sand 



^ 



Heavy Green Sand 



H - ' VMedium , 




Light 



Carpenter 
j Shop I 

Fig. 186. Typical Plan of Foundry 

fans, situated generally toward the ends of the shop, draw fresh air 
in through a compact system of steam coils, and, by means of over- 
head piping, deliver, it to all portions of the shop. The impure gases 
are carried off through ventilators in the clearstory at the top of 
the roof. 

Floor. The floor of the foundry should consist of molding sand, 
the depth of the sand floor varying with the class of work to be done. 
If the natural soil of the grounds is open and porous, a thickness of 
3 or 4 inches of clay, well rolled down, should be put in underneath 



184 



FOUNDRY WORK 



the sand floor. This will help greatly in keeping the molding floor in 
good condition, as it prevents the moisture draining out of the sand. 

Shop Office. The foundry office should be located at such a 
point that the foreman can command a view of the whole shop. It 
should be convenient to the different departments and at the same 
time be protected as far as possible from dust. The office room, 
shown in Fig. 186 at A, is built on the outside of the main building, 
but has a large bay window which projects a few feet into the shop 
from which all corners of the foundry can be seen. 

Pattern Room. A space J5, having suitable low tables and shelv- 
ing, is reserved near the offlce for the temporary storing of patterns 
in daily use. This brings them directly under the attention of 
the foreman and his assistants who can readily check the patterns 
as they come in and quickly find those requiring prompt attention. 




Fig. 187. Typical Elevation of Foundry 

Cupolas. At C are shown the cupolas, directly opposite the 
foreman's office, and so situated that all of the molding floors may 
be served as quickly as possible without interfering one with the 
other. 

In large foundries there are two or more cupolas, to admit of 
different mixtures being melted simultaneously. Often a compara- 
tively small cupola is installed near the floor for light work for the 
service of that floor alone. 

The blowers should be placed near the cupolas, avoiding long 
connecting wind pipes. The application of electric motors removes 
the necessity of concentrating the power at one point in the shop. 

Molding Divisions. Heavy Work. The main bay of the foundry 
is devoted to the heaviest work and is served by at least two 
overhead cranes. 



FOUNDRY WORK 



185 



The heavy green-sand castings are made at one end so that the 
flasks for this work may be stored in yards near by and be brought in 
through the door P. These molds are made up farthest from the 
cleaning shed, because only the castings themselves need be trans- 
ferred there. 

The flasks and rigging for the dry-sand and loam molds should 
be brought in through the opposite door E. The loam work, as a 
rule, is the most bulky to handle and should be nearest the cleaning 




Loft Abo\/e 
Moulding Machines 



Fig. 188. Automatic Sand Mixer 

sheds so that it need not be carried across the other floors. Both 
dry-sand and loam floors are convenient to the large ovens F . 

Core Shop. The core shop is situated in the side bay at G, to 
make it convenient to swing the large cores on to the buggies to be 
run into the large ovens. A jib crane near the corner of these ovens 
makes the men w^orking on such cores independent of the traveling 
crane. The ovens for small cores are built along the side of the 
large ovens and utilize the same stoke hole, ash pit, and stack. 

Light Work. Distributed through the side bays also are the 
medium-work floor H, the light-work floor /, and the molding- 
machine floor J. This ensures a supply of good light necessary to 
the smaller details of this class of work. 



186 FOUNDRY WORK 

Machines. The molding machines are placed on that side of 
the shop near the sand storage sheds, to allow for handling the sand 
by means of belt conveyors with hoppers above the machines, an 
illustration of which is shown in Fig. 188. 

The sand-mixing space is in the side bay near the cupolas at K, 
and is furnished with power from independent motors or from a jack 
shaft leading from the blower room. This position affords direct access 
to the sand bins. The raw material after being mixed and tempered is 
delivered by barrow or sand car direct to the]various floors. The mix- 
ers might be installed in one of the storage vaults across the roadway. 

Materials. Unloading. The quickest means of unloading either 
wagon or carload lots of material is by dumping, where the material 
can be so handled. One of two things is necessary to accomplish 
this: either the storage bins must be placed in a basement under- 
neath the roadbed; or the roadway must be run up an incline over 
the top of the bins. The former method is more frequently met with 
in the crowded condition of the large cities, but the latter is preferable 
because less time is consumed in running material up an incline in 
large quantities than is required to hoist small quantities more 
frequently from a basement. 

Storage. At L and L\ Figs. 186 and 187, are shown the storage 
yards for pig iron and coke; these are on a level with the charging 
platform of the cupola, C and C", and the materials can be loaded 
on cars and pushed directly to the charging door. In some modern 
shops these push cars are built so that their load may be dumped 
as a whole into the cupola. 

The storage for core-oven fuel, sands, and clay, is shown at 
MM, in bins built underneath the tracks and on a level with the 
foundry floor. These bins should be arranged to open on top, with a 
chute under the track and a trap at the side, so that coal or sand may 
either be dumped or shoveled directly into them. 

Handling Systems. Tracks. In the largest shops a standard- 
gage track should run directly through the main foundry, and there 
should be also similar tracks through the roadway next the cupola 
bay for convenience in removing the dump. The track over the 
storage bins has been mentioned. 

Two methods of transferring material between departments 
within the shop, aside from the cranes, are the overhead-trolley 



FOUNDRY WORK 



187 



system, Fig. 189, and the narrow-gage industrial railway. The 
former is of advantage in manufacturing plants where the loads to 
be transferred are nearly uniform in weight and frequency of hand- 
ling. This system leaves gangways smooth and free from obstruc- 
tions. For general work, however, the industrial railways are more 
frequently installed. These serve all floors to deliver flasks, sand, or 
iron, and to remove castings. 

Cranes, Of the many styles of overhead traveling cranes that 
are on the market, those using electricity as the motive power are 
undoubtedly the most 
serviceable. The cranes 
in the main foundry in- 
dicated at 0', Fig. 187, 
should have two hoisting 
drums on the carriage; 
one for such light work as 
handling flasks, rigging, 
and patterns; the other 
for the heavy work on the 
large ladles and castings. 

Small jib cranes fur- 
nished with a 2- to 4-ton 
air or electric hoist placed 
on the side of a man's floor 
make it possible for the 
molder and helper to han- ^^^" ^^^ 

die work of considerable size by themselves, and prevent loss of time 
from waiting for the overhead crane. 

The method of distributing the melted metal varies with the 
class of work made. In shops doing general jobbing work, the ladles 
for pouring the largest work are carried from the cupola directly 
by the overhead cranes. 

Bay Floor, For serving the floors in the bays one of the systems 
mentioned above is generally used. The metal is conveyed to the 
floor in a large ladle and from this smaller ones are filled and carried 
by hand or by a small crane to the molds. 

Cleaning Department. The cleaning department should be 
situated at one end of the shop near E, Fig. 186, or in a shed extension 




erhead Track and Trolley 



188 FOUNDRY WORK 

to the foundry proper. It requires space to pile the castings as they 
are brought from the floors with sufficient room for the men to begin 
work on these piles. As a rule, the smaller castings are first collected 
and put through the tumbling barrels, then the medium work is 
cleaned by hand or by sand blast; this leaves room for work around 
the largest pieces. As soon as castings are cleaned they are weighed 
and shipped to the customer, store house, or to the department which 
does the next operation upon them. 

PERFORMANCE 
LABOR 

Division. The division of labor in a foundry is briefly as follows : 

Superintendent. The superintendent is responsible for the 
operation of the foundry as a whole. He hires the men and oversees 
the purchase of materials and supplies, having under him clerks who 
keep track of the details of this work. Some of the things to which 
he gives personal attention are : In consultation with his foreman he 
gives personal attention to the receipt of the most important patterns; 
decides how they shall be molded; on what floor and with what 
mixture they shall be poured. He devises ways and means of increas- 
ing the productiveness of his shop. 

Foreman. The foreman or his assistants must be in the shop 
a sufficient time before work begins for the day to see that each 
molder has work laid out for him, and must keep the men supplied 
with work through the day. He estimates the amount of the charge 
for the day and directs the melter as to mixtures. 

It is the duty of the foreman and his assistants to give directions 
to the apprentice boys and to see that these directions are carried 
out to the best of the boys' ability. 

Holders. The molders should give their entire time to making 
up molds. On floor work they are usually given a helper who carries 
flasks, cores, chaplets, etc., and does the heavier work when handling 
the sand. When the molds are poured and his flasks stripped off 
the molder is through for the day. 

Laborers. Most modern shops employ a night gang of laborers 
to put the shop in proper shape for the molders to start their special 
work immediately when the whistle blows in the morning. These 
men remove the castings from the sand and transfer them to the 



FOUNDRY WORK 189 

cleaning shed. They pick out all bars and gaggers used in the molds 
and stow them in place. They temper and cut the sand and dig any 
pits necessary for bedding in work. 

SAFETY FIRST 

Accident Prevention. While it may be an impossibility to wholly 
prevent accidents in and about the foundry, much has been accom- 
plished in that line. Mechanical safeguards are now in pretty general 
use in modern foundries. It is only the out-of-date shop which is 
conspicuous for neglect in providing them. 

Personal Factor, Only some of the more important items regard- 
ing safety are called to the reader's attention, and perhaps the most 
important one of all is to teach the workman to think safety first. 
As an example, in a foundry employing 850 men there were, during a 
period of 6 months, 57 accidents involving loss of time. Not one of 
these was due to the lack of mechanical safeguards; all were results 
of carelessness on the part of the injured, or of negligence by their 
fellow workmen. 

Clothing, A large percentage of accidents in the foundry are 
in the nature of burns from hot metal, and again by far the greater 
part of these are below the knee. This shows the practical necessity 
for a legging of some material which would resist the hot metal. All 
employes in the foundry who come in contact in any manner with 
the work of pouring, or of shaking out flasks after pouring, when the 
hot sand may be just as dangerous as the molten metal, should be 
compelled to wear the foundry or congress shoe. 

Bhojp Equipment, There should be frequent inspection of all 
foundry rigging, such as crane hooks, chains, and ladle shanks, also 
great care should be used under the cupola and tapping spout, as 
any excess of moisture, were molten metal to be spilled upon it, 
would cause explosions and probably seriously injure someone. 

In the cleaning room, protection for the eyes from flying chips 
of metal is important; so, also, are guards over grinding wheels which 
should be equipped with an efficient exhaust to care for dust. 

While there are many more things which might be mentioned 
regarding safety, as applied to foundry practice, those already men- 
tioned should be sufficient to cause the student to think safety, to 
put his thoughts in practice and to teach others to do likewise. 



190 



FOUNDRY WORK 



PHYSICAL RESULTS 

Checking. The methods of mixing iron by analysis have been 
previously dealt with, but these mixtures must be checked by physi- 
cal tests on the resulting castings. Two systems of checking are 
now in more or less general use throughout the United States. 

Keep's Mechanical Analysis. A very complete system of regu- 
lating mixtures, termed by the inventor Mechanical Analysis has 
been devised by W. J. Keep, of Detroit, INIichigan, w^ho has had long 
experience in this subject. In Fig. 190, A shows a follow board 
arranged with patterns and yokes. The test bars are J inch square 
and 12 inches long. They are cast in green sand with their ends 
chilled against the faces of the cast-iron yokes, shown in the cut. 
Three molds should be cast each heat, and the test bars allowed to 
cool in the molds. 

Silicon and Shrinkage, The analysis is based on the fact that 
silicon is the most important variable chemical element in cast iron. 




Fig. 190. A — Keep's Test-Bar Pattern; B — Measuring Shrinkage 

and that shrinkage in castings is inversely proportionate to the 
silicon in the mixture. 

The first test, as shown at B, Fig. 190, is to replace each bar in 
the same yoke in which it was cast and by means of a specially 
graduated taper scale to ascertain accurately the amount of shrinkage. 

The shrinkage of the bars when the castings prove satisfactory, 
should be considered the standard for that class of work for that 
shop. If at any time the shrinkage is greater than the standard, 
increase the silicon by using more soft pig; if it is less, decrease 
silicon by using more scrap or cheaper iron. 

Chilled Depth. The depth of chill on the castings is measured 
after chipping off a piece from the end of the bar. 

Transverse Strength. The third test is to obtain the transverse 
strength of each bar. This is done on a special testing machine 



FOUNDRY WORK 



191 



"h 



L-rJ 

r-4 ~ 



which gives a graphical record of the deflection and the ultimate 
breaking load. These dead loads will vary with different mixtures 
approximately from 340 to 500 pounds. 

Deductions. Quoting from Mr. Keep's circular: 

With high shrinkage and high strength of a |-inch square test bar, heavy 
castings will be strong but small castings may be brittle. 

With low shrinkage and high strength, large castings will be weak and 
small castings will be strong. 

With uniform shrinkage, an increase in the strength of a §-inch square 
test bar will increase the strength of all castings proportionately. 

Arbitration=Bar Tests. The other form of tests was devised 
by a committee of the American Foundrymen's Association, and is 
recommended in the Proposed Standard Specifications 
for Gray- Iron Castings by the American Society for 
Testing Materials. 

Test Bar. The test bar specified is IJ inches in 
diameter and 15 inches long, and is known as the 
arbitration bar. 

The tensile test is not recommended, but, if called 
for, a special threaded test piece is turned down from 
the arbitration bar, and has a test section 0.8 inch in 
diameter and 1 inch between shoulders. 

The . transverse test is made with supports 12 
inches apart. 

Fig. 191 shows a sketch of the patterns for these 
bars. Tw^o bars are rammed in a flask and poured 
on end. The small prints on the two bar patterns 
project into the cope and are connected by one pouring 
basin. A special green-sand mixture is specified for 
making these molds; the molds are to be baked before 
pouring, and the bars allowed to remain in the sand 
until cold. 

Specifications. Table IX shows the specified requirements; 
in this connection castings are distinguished as follows : 

Unless furnace iron is specified, all gray castings are understood . to be 
made by the cupola process. 

Light castings are those having any section less than ^ inch. 
Heavy castings have no section less than 2 inches. 
Medium castings are those not included in the above. 



— /4- 



.^ , .^^ffjnn. 



HiH 



J. 



Fig. 191. Pat- 
tern for Arbi- 
tration Bar 



192 



FOUNDRY WORK 



TABLE IX 
Arbitration=Bar Standards 



Grade of Castings 


Chemical Prop- 
erties 


Physical Properties 


Sulphur Content 
High Limit 
(per cent) 


■Transverse Test* 

JMinimum Load 

(lb.) 


Tensile Strength 

Low Limit 
(lb. per sq. in.) 


Light 

Medium 

Heavy 


. 08 2500 

.0.10 2900 

0.12 3300 


18,000 
21,000 
24,000 



PRACTICAL DATA 
Using Percentage 

(1) To find the percentage of any number when the rate per 
cent is given : Multiply the number by the rate per cent and set the 
decimal point two places to the left. 

Example: Find 7.5 per cent of 35. 35X7.5 = 262.5; decimal 
point moved two places to the left gives Ans. 2.625 

(2) To find what rate per cent one number is of another: 
Add two ciphers to the percentage and divide by the number on 
which the percentage is reckoned. 

Examyle: What per cent of 75 tons is 9 tons? 900^75 = 12. 

Ans. 12 per cent 

(3) To find a number when the rate per cent and the percentage 
are known: Add two ciphers to the percentage and divide by the 
rate per cent. 

Example: If 68 pounds is 15 per cent of the entire charge, how 
many pounds in the total charge? Ans. 6800 -^ 15 = 453.33 pounds 

(4) To find what number is a certain per cent more or less 
than a given number: (a) When the given number is more than the 
required number, add two ciphers to the number and divide by 100 
plus the rate per cent. 

Example: 465 is 35 per cent more than what number? 

Ans. 46500-^(100+35)135 = 344.4 

(b) W^hen the given number is less than the required number 
add two ciphers to the number and divide by 100 minus the rate 
per cent. 

*In no case, shall the deflection be under 0.10 of an inch. 



FOUNDRY WORK 



193 



Storage Data 

Square Box Measure 



Size 
(inches) 


1 

Capacity 


24 X16 X28 

16 Xl6fX 8 

8iX Six 4 

4 X 4iX 4 


1 barrel 
1 bushel 
1 gallon 
1 quart 



Molding Material Weights 



Matekial 


Amount 
(cu. ft.) 


Weight 
(ton) 


River sand 
Pit sand 
Stiff clay 


21 
22 

28 


1 
1 

1 



Example. 526 is 23 per cent less than what number? 

Ans. 52600 ^(100 -23) =52600 -77 = 683, 116 



Mensuration 



Circumference of a circle 
Area of a square or rectangle 
Area of a triangle 
Area of a circle 
Convex surface of a cylinder 
Convex surface of a sphere 
Contents of a rectangular solid 
Contents of a cylinder 
Contents of a sphere 

One side of square having same 
area as given circle 



: diameter X 3. 1416 
^base side X height 
=baseX|Xperpendicular height 
■■ diameter squared X .7854 
■■ circumference X height 
■■ circumference X diameter 
^area of base X height 
^area of base circle X height 
^cube of diameter X. 5236 

fdiameterX.8862 
■A or 

I circumference X .2821 



Conversion Factors 


Inches 


X 0.08333 


Square inches 


X 0.00695 


Cubic inches 


X 0.00058 


Cubic inches 


X 0.004329 


Cubic feet 


X1728 


Cubic yards 


X 27 


U. S. gallons of water X 8 . 33 


U. S. gallons of water X 231.00 


Pounds of water 


X 27.72 


Ounces of water 


X 1.735 



= feet 
= sq. feet 
= cu. feet 
= U. S. gallons 
= cu. inches 
= cu. feet 
= pounds 
= cu. inches 
= cu. inches 
= cu. inches 



194 



FOUNDRY WORK 
Circular Areas and Circumferences 







H 







H 






K 






M 






U 













C 









K 




!5 






% 






^ 






^ 






H 


« 




H 


« 




H 


K 




a 


H 




K 


H 




K 


« 




K 


W 




U 




<! 


1^ 


H 


< 


H 


h 


< 


H 


h 


<: 


S 


S 


& 


fe 


H 


H 


s 


a 


S 


b 


H 


'A 


^ 


■< 


tf 


g 


s 


« 


% 


S 


« 


S 


s 


« 


S 


Q 


<1 


P3 




< 


& 

§ 


< 


< 




< 



< 








6 






6 






5 ■ 









1 


0.0123 


.3926 


10 


78.54 


31.41 


30 


706.86 


94.24 


65 


3318.3 


204.2 




0.0491 


.7854 




86.59 


32.98 


31 


754.76 


97.38 


66 


3421.2 


207.3 


0.1104 


1.178 


11' 


95.03 


34.55 


32 


804.24 


100.5 


67 


3525.6 


210.4 


1 


0.1963 


1.570 




103.86 


36.12 


33 


855.30 


103.6 


68 


3631.6 


213,6 


1 


0.3067 


1.963 


12' 


113.09 


37.69 


34 


907.92 


106.8 


69 


3739.2 


216.7 


i 


0.4417 


2.356 




122.71 


39.27 


35 


962.11 


109.9 


70 


3848.4 


219.9 


1 


0.6013 


2.748 


13' 


132.73 


40.85 


36 


1017.8 


113.0 


71 


3959.2 


223.0 


1 


0.7854 


3.141 




143.13 


42.41 


37 


1075.2 


116.2 


72 


4071.5 


226.1 


i 


0.9940 


3.534 


14' 


153.93 


43.98 


38 


1134.1 


119.3 


73 


4185.3 


229.3 


i 


1.227 


3.927 




165.13 


45.55 


39 


1194.5 


122.5 


74 


4300.8 


232.4 


1 


1.484 


4.319 


15' 


176.71 


47.12 


40 


1256.6 


125.6 


75 


.4417.8 


235.6 


X 


1.767 


4.713 




188.69 


48.69 


41 


1320.2 


128.8 


76 


4536.4 


238.7 


i 


2.078 


5.105 


le' 


201.06 


50.26 


42 


1385.4 


131.9 


77 


4656.0 


241.9 


a 


2.405 


5.497 




213.82 


51.83 


43 


1452.2 


135.0 


78 


4778.3 


245.0 




2.761 


5.890 


17' 


226.98 


53.40 


44 


1520.5 


138.2 


79 


4901.6 


248.1 


2' 


3.141 


6.283 




240.52 


54.97 


45 


1590.4 


141.3 


80 


5026.5 


251.3 




3.976 


7.068 


18' 


254.46 


56.54 


46 


1661.9 


144.5 


81 


5153.0 


254.4 




4.908 


7.854 




268.80 


58.11 


47 


1734.9 


147.6 


82 


5281.0 


257.6 


a 


5.939 


8.639 


19' 


283.52 


59.69 


48 


1809.5 


150.7 


83 


5410.6 


260.7 


3^ 


7.068 


9.424 




298.64 


61.26 


49 


1885.7 


153.9 


84 


5541.7 


263.8 




8.295 


10.21 


20' 


314.16 


62.83 


50 


1963.5 


157.0 


85 


5674.5 


267.0 




9.621 


10.99 




330.06 


64.40 


51 


2042.8 


160.2 


86 


5808.8 


270.1 




11.044 


11.78 


21^ 


346.36 


65.97 


52 


2123.7 


163.3 


87 


5944.6 


273.3 


4* 


12.566 


12.56 




363.05 


67.54 


53 


2206.1 


166.5 


88 


6082.1 


276.4 




15.904 


14.13 


22' 


■ 380.13 


69.11 


54 


2290.2 


169.6 


89 


6221.1 


270.6 


5' 


19.635 


15.70 




397.60 


70.68 


55 


2375.8 


172.7 


90 


6361.7 


282.7 




23.758 


17.27 


23' 


415.47 


72.25 


56 


2463.0 


175.9 


91 


6503.8 


285.8 


& 


28.274 


18.84 




433.73 


73.82 


57 


2551.7 


179.0 


92 


6647.6 


289.0 




33.183 


20.42 


24' 


452.39 


75.39 


58 


2642.0 


182.2 


93 


6792.9 


292.1 


1 


38.484 


21.99 




471.43 


76.96 


59 


2733.9 


185.3 


94 


6939.7 


295.3 




44.178 


23.56 


25' 


490.87 


78.54 


60 


2827.4 


188.4 


95 


7088.2 


298.4 


s' 


50.265 


25.13 


26 


530.93 


81.68 


61 


2922.4 


191.6 


96 


7238.2 


301.5 




56.745 


26.70 


27 


572.55 


84.82 


62 


3019.0 


194.7 


97 


7389.8 


304.7 


9' 


63.617 


28.27 


28 


615.75 


87.96 


63 


3117.2 


197.9 


98 


7542.9 


307.8 




70.882 


29.84 


29 


660.52 


91.10 


64 


3216.9 


201.0 


99 


7697.7 


311.0 



Weight Calculation 

Weight of round iron per foot = Diameter (quarter inches) squared X 0.1666 
Weight of flat iron per foot = Width X thickness X 3 .333 
Weight of plates per sq. ft. =5 pounds for each \ inch in thickness 
Weight of chain = Diameter squared X 10.7 (approximate) 

Safe load (pounds) for chain =Bar diameter (quarter inches) squared X 

2000 
To compute weight of metal from weight of pattern, with no allowance for 
cores or runners, multiply as follows : 

Multiplication Factors 



White Pine 


Mahogany 


Result 


16.7 


. 10.7 


Cast iron 


18 


12.2 


Brass 


23 


15. 


Lead 


15 


9. 


Tin 


16 


10.4 


Zinc 



Weight of brass pattern X . 9 = weight of iron casting, approximately. 



FOUNDRY WORK 



195 



Specific Gravities and Weights of Metals 




Specific 


Weight per 


Material 


Cubic Inch 






(pounds) 


Water, at 39 . 1° F. 


1. 


.036 


Aluminum 


2.6 


.094 


Antimony, cast 6 . 64 to 6 . 74 


6.7 


.237 


Bismuth 


9.74 


.352 


Brass, cast 7.8 to 8.4 


8.1 


.30 


Bronze 8.4 to 8.6 


8.5 


.305 


Copper, cast 8.6 to 8.8 


8.7 


.32 


Gold, pure, 24 carat 


19.25 


.70 


Iron, cast 6 . 9 to 7.4 


7.21 


.263 


Iron, wrought 7 . 6 to 7.9 


7.77 


.281 


Lead 


11.4 


.41 


Mercury, at 60° F. 


13.58 


.49 


Platinum 21. to 22. 


21.5 


.775 


Silver 


10.5 


.386 


Steel, average 


7.8 


.283 


Spelter or zinc 6 . 8 to 7.2 


7. 


.26 


Tin, cast 7 . 2 to 7.5 


7.35 


.262 



Pressure In Molds 



Depth 


Pounds 


Depth 


Pounds 


Depth 




Pounds 


(ft.) (in.) 


(per sq. in.) 


(ft.) (in.) 


(per sq. in.) 


(ft.) (in 


) 


(per sq. in.) 


1 


.26 


19 


4.94 


3 


6 


10.92 


2 


.52 


20 


5.20 


4 




12.48 


3 


.78 


21 


5.46 


4 


6 


14.04 


4 


1.04 


22 


5.72 


5 




15.60 


5 


1.30 


23 


5.98 


5 


6 


17.16 


6 


1.56 


2 00 


6.24 


6 




18.72 


7 


1.82 


25 


6.50 


6 


6 


20.28 


8 


2.08 


26 


6.76 


7 




21.84 


9 


2.34 


27 


7.02 


7 


6 


23.40 


10 


2.60 


28 


7.28 


8 




24.96 


11 


2.86 


29 


7.54 


8 


6 


26.52 


1 00 


3.12 


2 - 6 


7.80 


9 




28.08 


13 


3.38 


31 


8.06 


9 


6 


29.64 


14 


3.64 


32 


8.32 


10 




31.20 


15 


3.90 


■ 33 


8.58 


10 


6 


32.76 


16 


4.16 


34 


8.84 


11 




34.32 


17 


4.42 


35 


9.10 


11 


6 


35.88 


1 6 


4.68 


3 00 


9.36 


12 




37.44 



To find the total lifting pressure on the cope, multiply the pressure per 
square inch at a given depth below the pouring basin by the area (square inches) 
of the surface acted against. The result is in pounds. 



196 



FOUNDRY WORK 
Tern perat u res* 





Heat 


Connection 


(Degrees 




Fahrenheit) 


Core ovens 


250 to 450 


fyellow 


435 


Bright iron becomes jP^^^q 


500 
550 


[gray 


750 


Tin melts 


445 


Mercury boils 


660 


Lead melts 


612 


Zinc melts 


775 


Silver melts 


1775 


Copper melts 


1885 


Gold melts 


1900 


fa dark room, just visible 


950 


Iron bar red in < ordinary office 


1075 


1 daylight, open air 


1450 


Cast iron melts \^^^^^ 


2075 
2230 


Steel melts 


2750 


Annealing malleable iron 


1600 to 1750 



*From late scientific investigations. 



INDEX 



[ 



INDEX 



PAGE 

A 

Air furnace for melting malleable iron 154 

Alloys, brass and bronze 167 

Analysis of cast iron 190 

arbitration bar 191 

Keep's mechanical 190 

Analysis of cupola mixtures, chemical 123 

Annealing malleable-iron castings 161 

oven for 165 

Annealing steel castings 144 

Arbitration-bar tests of cast iron 191 

specifications for 191 

test bar in 191 

Arbors for core work. _ _56, 63 

B 

Balanced cores 60 

Barrel cores, making 92 

Batch sand mixer 152 

Binders, core 9, 47, 51 

Blast 112 

fan-blower 112 

gage for ^ 114 

pressure-blower 113 

Blowholes 22,31 

Bottom doors, cupola-furnace 109 

Brass 167 

chip separation 182 

cleaning castings of 181 

heats, size of 174 

melting 176 

molding equipment 172 

molding materials 171 

molding process 174 

pattern weight 194 

specific gravity and weight 195 

work, examples of 175 

Brass work 167 

alloys in_ 167 

production processes in 171 

Breast, cupola-furnace 111 

Bronze 168 

specific gravity and weight of 195 



2 INDEX 

PAGE 

c 

Carbon 121, 136 

Cast-iron analysis 190 

Casting operations 109 

brass work . 167 

malleable practice 145 

melting gray iron 109 

steel work 136 

Centrifugal sand mixer 129 

Chaplets 21 

setting _ _ 60 

Charcoal foundry facing . ^ 7 

Charging door, cupola-furnace 112 

Cheek ___:__ 9 

Clamps 17 

Clay wash ^ 8 

Cleaning castings, methods of 131 

malleable-iron work, in 160 

steel work, in 144 

Coke, foundry 126 

Cold-shuts , 31 

Cope - - 9 

flat joint, for 33 

floor bedding, in __*_ 44 

loam molding, in _• 99, 102, 105 

pressure head on 28 

Coping out - 35 

Copper 168 

specific gravity and weight 195 

temperature, melting 196 

Core-making machines 57 

Core ovens 48 

Core plates 48 

racks for 50 

Core sand 6, 46 

mixtures 51 

Core work 2, 46 

barrel : 92 

for brass molding 175 

dry-sand 46 

general equipment for 48 

green-sand 39, 62 

for malleable-iron molding ^ 152 

setting cores in 58 

for steel molding 141 

Core-rod straightening machine 134 

Cover core 90 

Cover plates in loam molding 95, 105 

Crucible malleable-iron melting 152 



INDEX 3 

PAGE 

Cupola furnace 109 

mixtures for 120 

operation of 116 

parts of 109 

Cupola malleable-iron melting 153 

Cutting and tempering sand 19 

D 

Drag 9 

fiat-joint 32 

floor-bedding pit . i 43 

Draw sticks .__ 17 

Drawback 100 

Drying stove for brass molds 173 

Dry-sand cores 46 

equipment for making 48 

methods of making 53 

materials for 46 

setting of 58 

use of 51 

Dry-sand molding 2, 89 

Duplicating of castings, multiple ^. 66 

brass 176 

gated-pattern method 67 

jolt ramming machine 79 

machine molding 67 

malleable-iron . 148 

permanent match 67 

roller ramming machine 86 

roll-over machine 73, 77 

squeezer machine 71, 75, 86 

stripping-plate machine 68 

F 

Facings 6 

dry-sand core . 47, 51 

for steel molding 137 

Ferrosilicon in malleable iron 158 

Fire clay 7 

Fire sand 5 

Flasks for 9 

brass molding — 172 

malleable-iron molding 152 

steel molding 138 

Flat joint 32 

Floor bedding -23, 42 

Foremen, duties of 188 

Foundry, typical 182 

cleaning department -- 187 



4 INDEX 

PAGE 

Foundry, typical (continued) 

core shop 185 

cranes 187 

cupolas 184 

floor plan 183 

heavy-molding division 185 

light-molding division 185 

molding machines 186 

pattern room 184 

shop oflfice 184 

storage of materials 186 

tracks ' 186 

type of building _' 183 

unloading of materials 186 

ventilation 183 

Foundry work 1-196 

casting operations 109 

molding practice. 1 

practical data 192 

shop management ^ 182 

Free sands 6 

G 

Gaggers 21 

Gas furnace for brass melting 179 

Gated patterns for duplicate castings 67 

Gating 24 

Graphite foundry facing 7 

Gray iron 109 

Green-sand cores 39, 62 

Green-sand molding 1 

principles of 18 

typical problems in 31 

H 

Hard-rolling of castings 160 

Heat, running a 116 

for brass work 174 

for malleable casting 159 

for steel casting 141 

I 

Iron 109 

specific gravity and weight of 195 

temperature indications 196 

J 

Jointing 32 

loam molds 100 



INDEX 5 

PAGE 

K 

Keep's mechanical analysis of cast iron 190 

chilled depth 190 

deductions by 191 

sihcon and shrinkage 190 

transverse strength 190 

L 

Labor, shop management of foundry 188 

foremen 188 

laborers 188 

moldera 188 

superintendent ,___ 188 

Laborers, duties of foundry 188 

Ladles for 118 

brass work 177 

malleable-iron work 159 

steel work 142 

Laying up loam mold 99 

Lead_._. 169 

melting temperature 196 

specific gravity and weight of: 195 

Lifters 15 

Lifting ring, core 40 

Lining 111 

cupola-furnace 111 

foundry-ladle 118 

Loam mixtures 92 

Loam molding 2, 94 

example of complex cylinder 104 

example of simple 102 

materials for 97 

principles of 99 

rigging for ^ 94 

M 

Malleable cast iron 145 

annealing 161, 196 

cleaning 1 160 

finishing 167 

melting, methods of 152 

metal characteristics 145 

method of casting 159 

methods of testing 146 

mixture for 156 

molding 148 

patterns for 148 

specifications for 146 



6 INDEX 

PAGE 

Malleable practice 145 

development of :_ 145 

production processes 148 

Manganese . 122, 136 

Match, sand -_ . .__ 36 

permanent oil 67 

Materials, molding 3 

brick for loam molding • 97 

cinders 98 

facings 6, 98 

miscellaneous 7 

mud for loam molding 98 

sands 3, 171 

Melting 109 

brass 176 

malleable-iron 152 

principles of iron 115 

steel - 141 

supplementary operations in iron 127 

Mixing machines, sand 128 

Mixing of sand I 127 

Mixtures, cupola-furnace 120 

calculation of 124 

chemical analysis of _ _ 123 

elements in 121 

fuel in 126 

proportions of charge in 126 

Mold board 9 

Molders, duties of 188 

Molding machines l 67 

Molding practice 1 

brass : 167 

divisions of iron molding ___. 1 

general molding equipment 3 

malleable-iron _, 145 

processes " 18 

steel - 137, 143 

N 

Natural-draft furnace for brass work 177 

Nowel or drag , 9 

O 

Open sand molding 45 

Open-hearth malleable-iron melting 156 

Open-hearth steel, casting 141 

P 

Packing steel molds 139 

Parting dusts 8 



INDEX 7 

PAGE 

Patterns for malleable castings 148 

Phosphor bronze 171 

phosphor tin in 171 

Phosphorus -_ 122, 136, 170 

Pickling castings 133 

of brass and bronze_ 181 

Pig iron in malleable work 157 

Pouring 119 

brass 174 

loam molds 104, 106 

malleable iron 159 

short 31 

steel i 142 

venting action during 23 

Practical data 192 

circular areas and circumferences 194 

conversion factors 193 

mensuration 193 

percentage, examples of using 192 

pressure in molds 195 

specific gravities and weights 195 

square box measure 193 

temperatures 196 

weight of metal and patterns 194 

weights, molding material 193 

Pressure in molds 27, 195 

pressure distribution examples 28 

pressure-head examples 28 

Pyrometer for annealing furnace __^ 167 

R 

Ramming :___ 20 

Ramming machine 79 

jarorjolt 79 

roller J 86 

Rammers 13 

core work, for 48 

Rapping plate 17 

Rattler or tumbling barrel 131 

Reinforcement, core 47, 55 

Risers . 22 

Roll-over machine 73 

power type 77 

Rotary sieve :__ 129 

Runners : 24 

S 

Safety-first factors 189 

clothing 189 

personal ' 189 



8 INDEX 

PAGE 

Safety-first factors (continued) 

shop equipment 189 

Sand shaker 129 

Sand-blasting ^ 135 

Sands, molding 3 

core sand 6, 46 

elements in 4 

fire sand 5 

for brass work ^ 171 

for malleable iron work 149 

for steel work 137 

free sands 6 

grades of 5 

green-sand mixture 18 

volume per ton 193 

Scabs - 31 

Scrap iron in malleable work 157 ' 

Sea-coal foundry facing 7 

Setting cores 58 

Shop management 182 

governing factors in 182 

labor 188 

of typical foundry 182 

physical results 190 

safety first in 189 

Shovel 12 

Shrinkage cracks 31 

Shrinkage heads or feeders 26 

Shrinkage in malleable casting 148 

Shrinkage in steel work 137 

Sieve, riddle or foundry 13, 129 

Sifting - 19 

Silicon - : 122, 136 

Skimming gate 24 

Slag hole, cupola-furnace 111 

Slicks 15 

corner 16 

Slip or skinning loam 94 

Snap flask , 9 

Spill trough for brass pouring 173 

Spindle for loam mold sweeping 94 

Split-pattern molds 38 

core Uf ting ring 40 

green-sand core 39 

loose-piece 1 39 

three-part 41 

Spraying can for core work 48 

Sprues 24 

Squeezer machine 71 



INDEX 9 

PAGE 

Squeezer machine (continued) 

automatic 86 

power type 75 

Steel 137 

annealing castings of 144 

casting, running a heat for 141 

cleaning castings of 144 

cores in molding 141 

facings for, mold 137 

flasks for molding 138 

molds for, setting up 143 

packing process in molding 139 

specific gravity and weight of 195 

temperature, melting ^ 196 

Steel work 136 

casting 141 

molding 137 

Stripping-plate machine. 68 

Sulphur 122, 136 

Superintendent, duties of 188 

Swabs 16 

Sweeping 95 

cores 56 

Swells 31 

T 

Tables 

alloys, proportions of mixtures in 170 

arbitration-bar standards for cast iron 192 

crucible sizes 176 

cupola-furnace sizes 112 

fan-blower performance 113 

flasks, sizes of wooden 11 

ladle data, foundry- 118 

phosphor-bronze mixtures 171 

sands, proportions of elements in ^ 4 

Tapping 117 

Tempering 19 

cores, dry-sand 47 

Testing cast iron 191 

malleable 146 

Three-part mold 41 

Tin - 168 

specific gravity and weight of 195 

temperature, melting 196 

Tools, hand-molding 9 

for finishing 14 

for brass work 172 

Trowels 15, 48 



10 INDEX 

PAGE 

Tumbling castings 131 

Tuyeres 111 

V 

Vent rods 1 16 

Ventilation systems in typical foundry 183 

Venting , 22 

dry-sand cores . ^ 47 

loam molds . . 100, 106 

W 

Warping 31 

White iron in malleable practice 149 

Z 

Zinc -- 169 

melting temperature 196 



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